Lecture #17: Landscapes Made Red: Military Geographies

Suggestions for Further Reading:

John Keegan, The Face of Battle (1976).

John M. Collins, Military Geography for Professionals and the Public (1998). A classic textbook survey of the role of different landscapes in times of war, available for free download here: https://archive.org/details/militarygeograph00collrich

Chris Pearson, Peter Coates, & Tim Cole, eds, Militarized Landscapes: From Gettysburg to Salisbury Plain (2010).

For an online version of the collection of maps that West Point designed for narrating the major battles and campaigns of the Civil War, see
https://www.westpoint.edu/history/SitePages/American%20Civil%20War.aspx

There are excellent, very detailed maps of major Civil War battles available on the website of the American Battlefield Trust: https://www.battlefields.org/learn/civil-war
Its maps for Gettysburg are here:
https://www.battlefields.org/learn/civil-war/battles/gettysburg

Allen C. Guelzo, Gettysburg: The Last Invasion (2013).

Michael Shaara, The Killer Angels (1974).

Craig L. Symonds, American Heritage History of the Battle of Gettysburg (2001).

Mark Adkin, The Gettysburg Companion (2008).

 

I. Introduction

Today's lecture surveys in just 75 minutes not only the Civil War, but also about military geography and landscapes of state-organized violence. We'll talk about the land-related issues leading up to the Civil War, step back to survey the role of landscape and geography in wartime generally, and then zoom in slowly to a very close reading of the role of landscape in the Battle at Gettysburg, regarded by many as the single most important turning point in the war.

II. Territorial Conflicts Leading Up to the Civil War

The territorial conflicts leading up to the Civil War were, in many ways, initiated right from the founding of the United States. We've already encountered them in our discussions of the Ordinances of 1785 and 1787. The question of how western territories would eventually enter the Union—as free states or as slave states—drove much of the politics of the antebellum (pre-war) period. We already saw last time the westward migration of cotton and slavery into the interior of the continent.

If we look out from the perspective of the new states as they began to debate the future of the new nation, we've already seen that a central question was how the lands known as the Northwest and Southwest territories would enter the Union once the war was over. Under the terms of the Northwest Ordinance, slavery was not to be allowed north of the Ohio River; the opposite assumption was made about lands south of the Ohio River. Thereafter, a recurring pattern was that new states entered the Union in pairs split north and south, one state prohibiting slavery, the other permitting it.

Under the terms of the Constitution, each state entering the Union received two seats in the Senate. This meant that the Senate could be counted on to represent the interests of individual states no matter how the differential growth of population in some states might unbalance the interests of individual states in the House of Representatives. This difference between the House and the Senate was written into the Constitution right from the start, and is the reason that rural areas are significantly over-represented in the Senate to this day, with consequences that are on vivid display in our politics in the twenty-first century. No gerrymandering is possible for the Senate, and only a constitutional amendment could change the way its seats are allocated.

From the point of view of pro-slavery southerners who feared that growing abolitionist sentiment in the more populous and rapidly growing northern states might muster a majority opposed to slavery in the House of Representatives, it was crucial that the balance of power not tip in the Senate. So one important way to understand American politics over the whole sweep of U.S. history is as a struggle for control of the Senate, which was designed to represent territory rather than population right from the outset.

The Missouri Compromise in 1820 regulated slavery in the country's western territories by prohibiting it in the Louisiana Territory north of the parallel 36°30′ north longitude, except within the boundaries of the proposed state of Missouri, where slavery would be permitted. This mean that, in theory, there would be no slavery north of 36°30′ north longitude.
https://en.wikipedia.org/wiki/Missouri_Compromise

As westward migration continued in such a way that northern territories grew more quickly than those in the south, and as abolitionist sentiment gained force, The terms of the Missouri Compromise began to erode. In an effort to arrive at a new modus operandi of north and south, free and slave, the Compromise of 1850 agreed to the following terms.
https://en.wikipedia.org/wiki/Compromise_of_1850
Notice how important land and territory were to these agreements, given the role they inevitably played in shaping congressional votes relating to slavery:

  • Texas surrendered claim to New Mexico, plus claims north of Missouri Compromise line.
  • California as admitted as a free state.
  • The Wilmot Proviso (which had banned slavery in lands acquired from Mexico in the 1848 Treaty of Guadaloupe Hidalgo) was nullified, declaring instead that citizens of new Utah and New Mexico territories should be given permission to decide by a vote of their residents whether slavery should be permitted within their borders (this came to be known as "popular sovereignty").
  • The slave trade was banned in the District of Columbia.
  • The Fugitive Slave Law strengthened, enabling southern slaveowners to seize their escaped "property" even when slaves fled north into states where slavery was prohibited (the Fugitive Slave Law was one reason why Canada was the ultimate destination for many who fled north to escape slavery).
    https://en.wikipedia.org/wiki/Fugitive_Slave_Act_of_1850

The Kansas-Nebraska Act of 1854 continued this trend of adjusting the terms of the Missouri Compromise as southerners sought to shore up their defense of slavery as an institution:
https://en.wikipedia.org/wiki/Kansas–Nebraska_Act

  • The law created Kansas and Nebraska as separate territories to increase the feasibility of a mid-latitude transcontinental railroad that seemed likely to built somewhere on this part of the Great Plains (as ultimately proved true of both the Union Pacific and the Kansas Pacific).
  • Crucially, the law established the principle of popular sovereignty for these two new territories, so that the decision of whether they would be slave or free would be decided by a vote of their inhabitants.
  • Since both Kansas and Nebraska were both north of 36°30′ north longitude, popular sovereignty effectively nullified the ban on slavery codified in the Missouri Compromise.
  • Pro- and anti-slavery advocates rushed to settle the new territories, especially Kansas, in a desperate effort to assure that any new territory or state there would join the Union. The violence that ensued came to be called "Bleeding Kansas":
    https://en.wikipedia.org/wiki/Bleeding_Kansas

Tension continued to mount with the Dred Scott Decision of 1857 (Dred Scott v. Sandford)
https://en.wikipedia.org/wiki/Dred_Scott_v._Sandford
in which the Supreme Court suddenly re-made the politics that had been struggled over until that time by affirming the following:

  • No person descended of Africans, slave or free, could be a citizen of the U.S. under the Constitution.
  • The Northwest Ordinance of 1787 could not confer freedom or citizenship on non-white individuals.
  • Missouri Compromise exceeded powers of Congress, and was therefore null and void (echoing the precedent set by the Kansas-Nebraska Act of 1854).

Notice in this description of events leading toward the Civil War how vast geopolitical contests were expressed on minute, very concrete and particular scales. The following can serve as just one among many examples: In Harper's Ferry, Virginia (now West Virginia), a fanatical abolitionist named John Brown decided he would take over the armory at Harper's Ferry, seize its armaments, distribute them to slaves in the South, and spark a mass uprising that would overthrow slavery forever. Federal troops arrived led by Robert E. Lee captured Brown, who was tried and eventually hung.
https://en.wikipedia.org/wiki/John_Brown%27s_raid_on_Harpers_Ferry

What finally triggered the Civil War itself was the election of 1860. The formation of the Republican Party in 1854, the splitting of the Democratic Party between free and slave Democrats, and the eventual election of Abraham Lincoln inescapably revealed the schisms that the United States had been struggling to evade for the "four score and seven years" that Lincoln so eloquently named at the start of the Gettysburg Address that will end this lecture. South Carolina seceded in 1860.
https://en.wikipedia.org/wiki/United_States_presidential_election,_1860
https://en.wikipedia.org/wiki/Confederate_States_of_America#Seceding_states

III. Military Geography

But let's step back before we turn to the Civil War. First, I want to talk about military geography generally. It may be unfamiliar to you, but if you want to think about the role of landscape in history, it's important to ponder the many ways that war -- the organized use of violence in pursuit of political ends -- typically expresses itself as territorial claims on land. Furthermore, the practice of war inevitably involves an intimate understanding of the myriad ways in which geography and landscape shape the ways violence can and cannot be deployed to achieve political power.

John Keegan's classic book The Face of Battle (1976) takes three separate and iconic wars—Agincourt (1415), Waterloo (1815), and Somme (1916)—and asks "What is the experience of war for an ordinary soldier, and how has that experience changed over time?" The question I want to ask in today's lecture is, "What's the terrain of war?

You can find many books written by and for the U.S. military on the terrain of warfare. Everything we've been talking about in this class is relevant to the fighting of war: slopes, transportation, where rivers block transportation, cities, the systems that allow cities to exist, the layout of streets, how roads are built, bridges, the needs of animals when they provide motive power, the role of petroleum and gasoline in power the trucks and automobiles that made transformed war in the era of Car Country (remember the Interstate and Defense Highways Act of 1956?)...all of these remind us that the details we've been exploring about the ordinary landscapes we all inhabit equally affect the landscapes of war.

Here are a few examples from today's lecture of military terrain shaping warfare. The bridge over the Rhine River at Remagen was, by March 1945, one of just two bridges across that river at the close of WWII. Controlling that bridge and keeping it operating was crucial: an example of a single location in a vast watershed and landscape that had crucial implications for the military forces for Germany and the Allied forces seeking to destroy Hitler's government.

Moving outward to a global scale, you can divide the whole world into different terrain conditions that imply very different consequences for military action: areas that are cold, where iceberg movements might affect shipping and where troops need to be kept from freezing; mountainous areas necessitating warm, lightweight and climbing equipment (that would spawn, incidentally, the 10th Mountain Division during World War II and the subsequent backpacking/camping gear industry in the U.S.); arid regions and tropical rainforests producing their own set of challenges of human dehydration or muddy roads and dense overgrowth. Shorelines are another example: the challenge of landing a ship on a beach and then determining how to fire from rapidly placed entrenchments on the shoreline is a big part of terrain analysis. It would also become a devastating feature of trench warfare during World War I. The landing of vast numbers of troops and machines—the landing of troops on the beaches of Normandy on D-Day for example—is a question of landscape, of geography.

 

IV. The Civil War: An Overview

So that's military geography in the abstract. Now let's look at the largest-scale military conflict ever to take place within the boundaries of the United States: the Civil War of 1861-1865.

I'm going to work my way towards the Battle at Gettysburg because it's such an important moment during the Civil War, and also because it furnishes so many vivid examples of the ways landscapes influence the course of battle. One virtue of Gettysburg from the point of view of a student is that today the battlefield is a national park which the National Park Service tries to maintain in conditions approximating (in some ways, at least) the way it appeared in July 1863. The signs and guidebooks available for interpreting the battle on the ground are as numerous as we have for any such event in American history, so it's an especially helpful place to try to learn how to read landscape history as it relates to nineteenth-century warfare.

Gettysburg remains the bloodiest battle ever fought on American soil, and arguably changed the course of U.S. history forever.

Before I get to Gettysburg, though, I need to return to the election of Abraham Lincoln in 1860. Certain southern states concluded almost immediately that Lincoln's election constituted an existential threat to the institution of slavery. South Carolina seceded on December 20, 1869, and six other states (Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas) all followed suit even before Lincoln's inauguration on March 4, 1861. Four remaining southern states (Virginia, North Carolina, Tennessee, and Arkansas) did not secede until South Carolina and the Confederacy began military hostilities by firing on Fort Sumter in Charleston Harbor on April 12-13, 1861.

To think about the ways military forces interact with landscapes, it's important to consider the different kinds of units into which 19th-century armies were divided:

  • infantry (soldiers marching or fighting on foot)
  • artillery (large-caliber guns and the troops operating them, for shelling enemy forces from a distance to support one's own infantry)
  • cavalry (soldiers moving, scouting, and fighting on horseback)
  • logistics (the movement and supplying of troops) Mark Fiege, whose scholarship you're reading for section this week, is especially good at tracing logistics: food, fuel for transportation, ammunition, gunpowder, guns. If you're trying to think through the military geography of a landscape, paying attention to logistics and how an army will be supplied will be crucial to understanding how and why a battle will be fought in particular ways on that ground.
    https://en.wikipedia.org/wiki/Military_logistics

After two days of shelling, U.S. Army Major Robert Anderson would cede Fort Sumter to South Carolina.
https://en.wikipedia.org/wiki/Battle_of_Fort_Sumter

Here's a key point that I hope you drew from last week's lecture: southern agriculture, particularly by the middle of the 19th century, was mainly designed for large-scale production for the export trade, most of it sold into international markets. The South did not mainly grow its own food, especially the cotton plantations of the lower Mississippi Valley. That these plantations were not producing their own food had significant implications, particularly if you're thinking in terms of logistics. How would these southern plantations feed themselves in time of war? As food became a growing problem, what would happen to the cotton production on which the income of the region depending (including for financing the war)?

Notice differing resources on the eve of the CIvil War: the North had a much larger industrial base and workforce than did the South. It had much more extensive railroad networks, which would become great logistical assets in time of war. Furthermore, the gauges (the distances separating rails) of southern railroads didn't match up in all parts of the South, making it impossible for trains to move interchangeably on all tracks in the region.

In the war that was to come, there was an additional problem: the nation's capital was located in the District of Columbia, set up in 1790. One of the compromises made at the time of the U.S. Constitution in 1789 was the decision to move the U.S. capital south from Philadelphia because Pennsylvania had outlawed slavery and any slave who had lived there for more than six months would be legally free. This created intolerable problems for southern politicians wishing to bring their slaves to the capital, so it was agreed that a new District of Columbia would be created on land excised from Virginia and Maryland, which at that time were the two largest slave states in the U.S.. This meant that D.C. was surrounded by slave states at the start of the Civil War, making the Union's defense of the nation's capital all the more challenging.

Even if you're not terribly interested in military history, I hope you'll take from this lecture some of the broad patterns whereby landscapes are implicated in the ways wars are fought. For instance, prior to the start of lecture, I showed a looping four-minute animated film (created for the Abraham Lincoln Presidential Library and Museum in Springfield, Illinois) in which you saw the boundaries of the Confederacy and the Union shift across the years 1861-1865. Again, watch for the large patterns. Watch what happens to the Mississippi River. Watch what happens in the area around Virginia. And watch at the end during William Tecumseh Sherman's famous March to the Sea. If you want to view it again, there's a low-resolution version of this animated map online at:
https://www.liveleak.com/view?i=09a_1448407705

Here's a map that West Point created to depict the most important battles and military campaigns of the Civil War on a single map:
https://www.westpoint.edu/history/SiteAssets/SitePages/American%20Civil%20War/ACW01.gif
Study this map, and you'll see that much of the most important fighting during the war took place in the Virginia-Maryland orbit, all within 100-200 miles of D.C. These would become some of the most decisive battles of the Civil War: Antietam, Gettysburg, and Petersburg all warrant our attention. Controlling the Mississippi River, unsurprisingly, was another imperative of the War, with the Battle of Vicksburg its culminating event.

 

V. Landscapes of Conflict: Toward Gettysburg

One way of thinking about the Civil War is as was a struggle over territory that the two armies were trying to control (with the larger goal, of course, of gaining the political control needed either to end or defend slavery). We already looked at Fort Sumter as an attack on a federal outpost that launched the Civil War. The Battle of Antietam (September 17, 1862) was the bloodiest single day of the Civil War, with 22,717 dead, wounded, missing. Gettysburg was the bloodiest single battle of the war, but it took place over three full days of fighting.

War on the ground is never abstract and is always governed by geography, which shapes how troops are able to move across and fight on a given landscape. Let's do a close geographical reading of several crucial Civil War conflicts to understand the role terrain played in shaping them.

The Battle of Antietam (as it was called in the North) was called by southerners the Battle of Sharpsburg, a common feature of the Civil War in which the two sides chose different place names to describe the same battle.
https://en.wikipedia.org/wiki/Battle_of_Antietam
The first stage of intense conflict at Antietam took place on "The Cornfield," as it has been known ever since. Fighting was so intense on this patch of land that after three hours of shooting, every stalk of grain was flattened. The next stage book place on an old sunken farm road that is today called "Bloody Lane," because hundreds of Union and Confederate troops died in the trench without being able to flee to safety. In the climactic conflict of Antietam, at "Burnside's Bridge" (as it was renamed for the Union general who sought to lead his troops across it), it took 3 hours for Union troops to get across a single stone bridge as Confederate forces fired down from nearby hillsides. Because the Confederate forces were higher and could fire from behind cover, while the Union forces had to move into the open onto the very exposed space of the bridge, Union casualties in that phase of the battle were much higher, enabling a smaller Confederate force to delay the larger Union force long enough for the bulk of Lee's army to escape.

Antietam represented enough of a victory for the Union that it demonstrates the ways in which war and politics interacted during the Civil War. The Union victory at Antietam on September 17, 1862, gave Lincoln the political momentum he needed to announce the Preliminary Emancipation Proclamation five days later, on September 22, 1862. It declared that slavery would be outlawed in any state that was still in rebellion against the Union on January 1, 1863. At the same time, the Union stepped up efforts to recruit southern slaves to abandon their plantations and head north to join the Union Army, thereby depriving the Confederacy of its most important workforce. The growing numbers of slaves who fled the South and joined Union military forces made crucial contributions to the ultimate Union victory. Nearly 200,000 black soldiers ultimately served in the Union Army and Navy--roughly 10% of those who fought for the North.
https://www.archives.gov/education/lessons/blacks-civil-war

Now let's briefly consider the western theater of the war, where control of the Mississippi River was a vital strategic goal for the Union to divide the Confederacy in two and to starve the cotton South. U.S. Admiral David Farragut for the Union forces began taking his fleet upstream from the mouth of the Mississippi River in April, 1862, seizing New Orleans on April 29 and placing it in Union hands. The campaign to claim Vicksburg, a Confederate stronghold on the Mississippi River in the state of Mississippi, was very difficult and eluded Farragut. (The bombardment and capture of Island Number Ten in the Mississippi near New Madrid led to the capture of Confederate troops who were brought back as prisoners of war to Camp Randall in Madison, Wisconsin, where many would die and be buried in Forest Hill Cemetery, making it the new northernmost Confederate cemetery in the United States.)

With Farragut's failure to take Vicksburg with naval forces alone, it was another military leader, Ulysses S. Grant, who first made his name at Vicksburg. He needed to move across this very wet, very difficult terrain in what amounted to a huge engineering challenge—and this was just on the west side of the Mississippi River, not the east side where Vicksburg was located and where the ultimate assault had to occur. Finally, on July 4, 1863, Union forces moved in and took over Vicksburg, so that the Union controlled the full length of the Mississippi for the duration of the War. (The Union victory at Vicksburg was almost simultaneous with the Union victory at Gettysburg.)

To get to Richmond, the Confederate capital, Union troops needed to go through Petersburg. Union forces dug trenches—creating a landscape that anticipated the brutal conditions of World War I—and a standoff began that lasted for 9 months.
https://en.wikipedia.org/wiki/Siege_of_Petersburg
Montgomery Meigs, the Quartermaster General of the U.S. Army, organized the supply lines for all the Union forces on this difficult terrain and stalemate. Everything we've talked about in this lecture relied on Meigs' moving materials to the front: troops, animals, food, materiel, guns, bullets, cannonballs, gunpowder, animals. How was this accomplished? Ships, dockworkers, horses, wagons, roads, bridges—and you built railroads. At Petersburg, Union forces built a railroad line from City Point (on the James River) to the trenches outside Petersburg holding Union soldiers.

The U.S. Army Corps of Engineers made crucial contributions to the success of all these logistical exercises, building pontoon bridges, trestle bridges, railroads, canals, all crucial for moving supplies. It's worth noticing that the history of transportation we've traced more than once in this course has been recapitulated as we've sought to understand how the Civil War was fought.

 

VI. Landscapes of Conflict: The Battle of Gettysburg

So let's zero in on just one small place to think about big themes of the Civil War and the role of landscape in war more generally: Gettysburg, Pennsylvania, from July 1-3, 1865.

The Wikipedia entry for the Battle of Gettysburg offers a good overview with excellent maps:
https://en.wikipedia.org/wiki/Battle_of_Gettysburg
You'll find an animated map of the battle here:
https://www.youtube.com/watch?v=vUKreep2P1M
and a detailed set of maps for following the day-to-day action here:
https://www.battlefields.org/learn/civil-war/battles/gettysburg
For a compelling novelistic narrative of the battle told from the points of view of many of the chief officers on both sides, Michael Shaara's The Killer Angels (1974) remains unsurpassed, and was the basis for the 1993 film Gettysburg. Allen C. Guelzo's Gettysburg: The Last Invasion (2013) is the best recent history.

Lee made the decision in June, 1863 to head north, to bring the war to the North. He wanted to encourage northerners who were unhappy about the war to demand that President Lincoln bring the war to an end, and bringing the violence of the conflict onto their home ground seemed the most effective way to do that. (It's easy to forget that the vast majority of Civil War battles took place in the South.) Lee also wanted to destroy the northern armies.

The North's chief commander, Joseph Hooker, trying to anticipate Lee, was unable to figure out the route of attack the Confederate troops were adopting. (Lincoln had lost confidence in Hooker by this time, as was true of a series of generals he put in charge of the Union Army, and replaced Hooker with George Meade on June 28...just three days before the Battle of Gettysburg began.) Meanwhile, Confederate Cavalry General J.E.B. "Jeb" Stuart made the long trip north and wouldn't arrive in Gettysburg until July 2nd, the second day of the battle. Lee was furious because the cavalry are the eyes of the army, and Lee was forced to start this crucial battle blind: Stuart was not present to tell him where the Union troops were located. Eventually both the Union and Confederate forces all converged on the tiny Pennsylvania town called Gettysburg.

Gettysburg is located between two ridges that played crucial roles at different moments in the battle. As we've already seen at Burnside's Bridge during the Battle of Antietam, the ability to control one of those ridges, and with it the high ground, offered commanding control of the low valley nearby in addition to the ridge itself. The first senior Union officer to arrive at Gettysburg was John Buford, a Brigadier General of the U.S. Cavalry. He determined that Confederate troops were massing to the west and decided that it was vital that the Confederates not gain control of the ridge running south of Gettysburg. Alhough Buford had only 2500 cavalry troops, which would not ordinarily be deployed to confront a much larger force of infantry, Buford decided to try to delay the arriving Confederates long enough for Union reinforcements to arrive. Buford's commanding general, John Reynolds, was killed almost immediately upon arrival at Gettysburg, but his troops arrived in time to replace Buford's cavalry, occupy the ridge, and hold the high ground.

As an aside, recalling the earlier lecture about the history of mapmaking, remember that it wouldn't be until 1884 that time became standardized with the establishment of the Greenwich Meridian and railroad-created time zones. This meant that everyone at Gettysburg (and other Civil War battlefields as well) set their watches to different local times. This inevitably created confusion, since troops coming in from the west would initiate different tasks depending on the time they were arriving. Union troops began to dig in and build fortifications that would be pivotal in the events at the battle to follow. Here's where the clock matters: should the Confederates have attacked to prevent these fortifications from being built, arguably a crucial turning point for solidifying the Union position? The answer to that question depended on what time in the day Confederate forces arrived, which is still unclear in the historical record because of the differing times to which generals set their clocks—so differing times are recorded in the historical documents we use today to try to understand the battle.

Another aspect of logistics on the battlefield that had implications for understanding the landscape was the location of medical facilities. Hospital tents were constructed to treat the wounded and dead. Sepsis and gangrene were major problems, so the amputation of limbs was often necessary to prevent injured soldiers from contracting these deadly diseases.

By the morning of the second day, July 2, 1863, Union forces were aligned in a hook shape along Cemetary Ridge and Culp's Hill, where serious fighting now took place. Union General Sickles rode out with forces to the end of Peach Orchard, leaving the ridge undefended. Union Brigadier General Gouverneur K. Warren, in response, moved his troops to the hill called "Little Round Top" to keep Confederate troops from charging uphill. The landscape below, littered with boulders, became known as "Devil's Glen" for all the soldiers killed trying to climb the hill and hide behind the boulders.

The 20th Division from Maine, led by Joshua Chamberlain, a professor of rhetoric and later president of Bowdoin College, commanded one of the most famous skirmishes of the battle in defending Little Round Top. After being ordered that he should not on any circumstances abandon the left flank—he was essentially ordered "You will die here"—even though his troops had minimal ammunition, the 20th Maine held the ground for two hours. After Chamberlain realized that his men had no ammunition left, he ordered his men to attach bayonets to their rifles and charge downhill toward the attacking Confederate forces. Incredibly, the Confederate forces gave way and the Union line held.
https://en.wikipedia.org/wiki/Little_Round_Top

The next day, Lee ordered an all-out assault on the Union forces massed on Cemetery Ridge. He began by ordering Edward Porter Alexander to launch an artillery barrage on Cemetery Ridge to prepare the way for the infantry charge that was to follow. In smoky conditions, the ability to aim cannons was poor, and most cannonballs overshot the ridge. This enormous artillery attack, despite its firepower, was not very effective, partly because it is so hard to aim accurately uphill. Lee then ordered a wide infantry charge (led in part by Major General George Pickett, for whom "Pickett's Charge" has forever after been named) across a mile of open ground and up Cemetery Ridge.
https://en.wikipedia.org/wiki/Pickett%27s_Charge

Troops in nineteenth-century regiments were organized into pairs to enable the line of men in front would fire, then fall back to reload while the line behind moved forward to fire, and so on. Lee's decision was that the enemy was weakest at the center of Cemetary Ridge, so he charged uphill with 15,000 troops. Remember, his strategic/tactical goal was not to conquer the North, but rather to break the Union Army and bring the war to the North in order to force Lincoln to sue for peace on southern terms.

The ability to have greater control of bullets traveling longer distance via changing arms technology helps explain the enormous casualties and number of amputees. Military technology intersected with geography to shape the concrete effects of the war: an enormous number of casualties.

Unable to break the Union lines, and having suffered devastating losses to his own troops, Lee ordered a retreat. The Union army was in no position to follow, so Lee was able to get away and the war would continue for another two more years. But Gettysburg (with Vicksburg) is now generally regarded as the High Water Mark of the Confederacy, which would never again be able to delivery hostile forces so far north on Union soil. The next two years were a long war of attrition.

It was at a cemetery on the site of this battle that Abraham Lincoln, on November 19, 1863, delivered what is arguably the greatest speech ever made by an American president: the Gettysburg Address.
https://en.wikipedia.org/wiki/Gettysburg_Address

Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal. Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battlefield of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this. But, in a larger sense, we can not dedicate, we can not consecrate, we can not hallow this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us—that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion—that we here highly resolve that these dead shall not have died in vain—that this nation, under God, shall have a new birth of freedom—and that government of the people, by the people, for the people, shall not perish from the earth.