A Map Study of the Battle of Gettysburg

Just as strategy, numerical superiority and advanced weaponry are assuredly conducive to military strength and thus victories, so too is the geography of the land on which battles are fought. According to military geologist, Professor Peter Doyle of University College London:
“Geology has controlled the outcome of battle since warfare began. Understanding the nature of ground, the opportunity for active defense and tunneling, the ability to move freely across tracts of terrain and the provision of natural resources are some of the problems that have faced armies for centuries.”
The Battle of Gettysburg proved no exception to this assertion.

Map Making during the Civil War: 
Map making constituted an integral part of military operations during the Civil War. For commanders, map making allowed them the opportunity to better understand the land over which their armies marched and fought. Commanders entrusted topographical engineers to undertake the task of mapping the topography of a given battlefield to ensure that they intimately understood the surrounding terrain. Prior to March 31, 1863, United States topographical engineers operated within their own corps or groups within the military and otherwise. Thereafter, however, topographical engineers were integrated into the United States Corp of Engineers and most officers had a topographical engineer on their staff. Throughout the Civil War, the Confederate Army suffered from a lack of topographical engineers, thus putting the north at an advantage. 
The first of the two maps used in conjunction with this lesson plan was produced by a topographical engineer during the battle, while the second was produced a few months after the battle, using eyewitness accounts from the townspeople, press correspondents, and extractions from diaries, for accuracy. Though little is written on the maps’ respective backgrounds, they accurately assess the situations during the three days of fighting at Gettysburg. They take into account the topography of Gettysburg, the strategic formations pursued by both the Army of Northern Virginia and the Army of the Potomac throughout the battle, while additionally providing specific dates and locations of certain units and brigades during the battle.
The first map, created by Captain and Aide-de-Camp, William Willcox of General John F. Reynolds’ Staff, who also served as his topographical engineer, shows much of the aforementioned. Willcox’s map provides the viewer with a macro-view of the battle situation at 2pm on July 2nd, just as the Army of Northern Virginia was preparing its assaults against the Union flanks. Furthermore, Willcox’s map provides depictions of railroads, road networks, infantry and artillery positions, the names of Union units as well as Corps and their commanders. Moreover, Willcox depicts Confederate battle formations, Union breastworks, and cavalry positions. Special attention is also given to vegetation, and civilian landmarks such as churches, and cemeteries.
Much like the first map, the second, created by Theodore Ditterline, a northern map maker, provides the viewer with an understanding of troop and artillery locations and movements, drainage ditches, road networks around the town, railroads, and houses with the names of residents, for all three days. In essence, these maps have the ability to tell the story of the Battle of Gettysburg through a different lens and at a macro level, allowing the viewer to see and understand the Gettysburg battlefield in its entirety, rather than in a fragmented micro-level manner. From a macro-level view, the viewer can also better understand the significance of geography during the battle, as it allows one to evaluate the entirety of the military situations throughout the battle, as opposed to isolating them.

Background of the Battle:
Following the Battle of Chancellorsville in May of 1863, a victorious Army of Northern Virginia, commanded by Robert E. Lee, decided to launch an invasion of the North. His rationale proved three fold: take the armies out of the war-ravaged Virginia countryside and into the abundant agricultural bastion of Pennsylvania, disrupt any offensive strategies of the Union army, and prevent the Union army from gaining reinforcements from other theaters. Using the Blue Ridge Mountains to shield his army’s movements, Lee moved north on June 3rd, followed closely by Union General Hooker. Towards the end of June, with the Confederate cavalry missing, and ignorant to the Union army’s movements, Lee learned from a spy that the Union army was actively moving north, forcing him to concentrate his forces in the vicinity of the town of Gettysburg, which sat at the hub of 10 major roads. Gettysburg's location made the likelyhood of an army passing through and a military engagement occurring there as a result, very high. Additionally, Hooker having resigned, the Army of the Potomac now fell under the command of General George Gordon Meade. Though Meade never intended for a battle to ensue at Gettysburg, Union cavalry under the command of John Buford, encountered Confederate infantry outside the town, thus prompting both commanders to rush troops to the small Pennsylvania town. The stage was set for the bloodiest battle in American history. 

Essential Questions

What role does analysis have in historical construction?
Why is time and space important to the study of history?


Students will be able to:

  • Recount the events of the Battle of Gettysburg.
  • Analyze natural features on a map.
  • Understand the role geography plays in military affairs.

Suggested Instructional Procedures

It is assumed that instructors have already begun their discussion of the Civil War, and its social, political and military implications prior to July 1863.

Begin lesson plan by discussing Gettysburg in terms of its impact and significance:

  • Destroyed Confederate hopes of a major victory on Union soil to end the war.
  • Destroyed any lasting Confederate hopes of European intervention.
  • For the most part, put Lee on the defensive for the remainder of the war.
  • Gave renewed hope to the Union war effort after a string of Confederate victories.
  • In just three days, Gettysburg resulted in over 40,000 casualties (both armies combined), making it the bloodiest battle in American history. 

1. Begin the lesson by describing the background of the battle (i.e. how a battle at Gettysburg came to fruition) using a large map of Pennsylvania. This is intended to give the students a broader perspective on Gettysburg’s location followed by a more narrow understanding of the town and the topography on which the armies fought.  

Pennsylvania State Map w/ Gettysburg

*As Professor and military geologist Peter Doyle convincingly asserted,

“Understanding the nature of ground, the opportunity [it offers] for…defense, the ability to move freely across tracts of terrain and the…[collection] of…resources are some of the problems that have faced armies for centuries.”  

2. Explain that Gettysburg location, at the hub of 10 major roads, made the passage of an army through the town, or the likelihood of a battle occurring there, very high.

3. Print and distribute and/or project images of either the Ditterline and/or Willcox map(s) on the board for students to see. Then split the students into 4 groups and assign one of the following questions to each group for reflection:

  • From looking at these maps, why might generals have deemed Gettysburg a suitable place to engage in battle?
  • What are Gettysburg’s geographical features?
  • Why and for whom do you think these maps were created?
  • What benefit, if any, would maps serve in battle?

4. While the students are working, write these questions down on the blackboard, under which to record their responses.

5. Bring the students back together at which time each group will provide responses to their respective questions.

6. After recording these responses, make note of the best ones as they will benefit the conclusion of the lecture.

7. Split the students into 3 groups. Each group will be given a description of the events during one day of the battle from this lesson plan as well the list of key terms.

8. Each group will study the description of the day’s events and upon completion, go to the front the class and present the events during the specific days of the battle. They will do this by tracing the troop locations, movements and points of attack on the board, throughout the days specified, using a marker with the projected map(s) as the backdrop.

9. After this activity, bring the students together, and pose the following question:

  • Do you notice a pattern which relates to the success of the Union army during the battle?
  • Should the students not know, proceed with the following steps:

10. Conclude the lesson by approaching the map(s), which have been doctored by the students’ previous activity, and begin circling the major topographical landmarks around which the battles centered during the 3 days.

  • On day 1, McPherson’s Ridge allowed the Union army to hold out until reinforcements arrived, thus preventing the Confederates from commanding the high ground south of town.
  • On day 2, the Union army’s position atop Little Round Top and Culp’s Hill prevented the Confederates from achieving their goal of flanking the Army of the Potomac.
  • On day 3, Lee’s decision to march across the open field which extended from Seminary Ridge to Cemetery Ridge to break through the Union center, allowed the Army of the Potomac to inflict massive casualties on Pickett’s division before it arrived at the ridgeline.

11. Before the students leave, read them the quote, enclosed in the lesson plan, from military-geologist Peter Doyle about the importance of topography and its significance in determining the outcome of battles for thousands of years:


12. For homework, have the students analyze this quote and write a 1 or 2 page response, as to how “The nature of ground…defense…the ability to move freely across tracts of terrain and the [collection] of…resources,” helped determine the outcome of the battle.  


Military Terms:

Artillery: A branch of the military armed with cannons or other large caliber firearms.

Barrage A large artillery attack.

Brigade: A large group of soldiers, commanded by a brigadier general. Brigades consisted of 4 – 6 regiments.

Caliber: The distance around the inside of a gun barrel. Bullets are labeled by what caliber gun they fit.

Cavalry: A branch of the military which was mounted on horseback. Cavalry could move quickly from place to place and gather intelligence on enemy army movements. Until 1863, Confederate cavalry often proved superior to their northern enemies. During the Battle of Gettysburg, Lee was unaware of his cavalry’s location and thus made many military decisions at a slight disadvantage. Confederate cavalry arrived on the night on July 2nd and partook in fighting behind Union lines on July 3rd. Their goal was to disrupt Union communication lines and meet up with Pickett’s infantry as they broke through the Union center. Union cavalry under the command of General George Armstrong Custer repulsed Confederate efforts.

Company: Small groups of soldiers within regiments which numbered 50 -100 men. Ten companies comprised each regiment.

Corp: A term adopted by the American military from the French after the Napoleonic Wars, Corps provided a means by which to organize large bodies of soldiers. Corps were comprised of 2 or more divisions. Corps existed in both Union and Confederate Armies and were designated by a Roman numeral to provide further structure and organization to the army.

Division: Another means by which the Union and Confederate armies provided structure and organization to large bodies of troops. Divisions consisted of 2 – 5 brigades.

“Fish-Hook” Formation: The Union army’s battlefield formation from July 2nd – 3rd resembled a fish-hook in shape, hence the name. The barb, or the hook, wound around Culp’s Hill to the North and ran along Cemetery Ridge, to Little Round Top to the south. This formation allowed Meade to transfer his troops from one area of battle to another, unscathed.

Flank: A flank is the end (or side) of an army’s position. Used as a verb, "to flank" is to move around and attack the side of an enemy’s position, to avoid a frontal attack.

Infantry: A branch of the military in which the soldier travels and fights on foot.

Musket: Principle firearm during the American Civil War. Could be rifled or smooth bore and was loaded from the muzzle or front of the barrel. Smooth bore muskets fired lead balls while rifled muskets fired conical (cone) shaped minié balls – named after Claude Minié, the French officer responsible for the bullet’s creation. 

Reconnoiter: The act by which one army inspects, observes, or surveys an enemy’s position to gain information for military purposes.

Regiment: Comprised of 10 companies and made up of 1,000 – 1,500 men. Four to five regiments often made up a brigade. 

Repulsed: Forced to retreat.

Theaters: Regions in which armies operate. During the Civil War, the Eastern Theater encompassed military operations in the states of Virginia, Maryland, and Pennsylvania, while operations conducted in the deep south occurred in the Western Theater.

Topography:  Study, surveying or mapping of the features and characteristics of a specific area of land.

Battle of Gettysburg Terms:

Army of Northern Virginia (ANV): The principle Confederate Army of the Eastern Theater during the Civil War. Southerners often named their armies and the battles in which they fought after geographical landmarks (i.e. Army of Northern Virginia and Battle of Sharpsburg).

Army of the Potomac (AOP): The principle Union Army of the Eastern Theater during the Civil War. As opposed to their southern enemies, northerners tended to name their armies and the battles in which they fought, after bodies of water. (i.e. Army of the Potomac and Battle of Antietam).

Cemetery Ridge: Ridge line south of Gettysburg, opposite to Seminary Ridge. Cemetery Ridge served as the position along which the Army of the Potomac formed their line and subsequently held from the evening of July 1 to the conclusion of the battle on July 3rd.

Culp’s Hill: Rocky hill located to the north along Cemetery Ridge. Culp’s Hill constituted the barb in General Meade’s “fish hook” formation. The peak was occupied by Union troops on July 1st and they held the position until the conclusion of the battle. During the evening of July 2nd and in the early morning of July 3rd, elements of Richard Ewell’s Corp tried desperately to take the hill but their efforts proved ineffective. The successful defense of Culp’s Hill prevented the Confederate Army from maneuvering the Army of the Potomac into a position from which the Army of Northern Virginia could situate itself between Meade’s army and Washington D.C.

Federal: Another name for a Union soldier.

Gettysburg: Town which sits in Adams County located in south-central Pennsylvania. From July1st – July 3rd, the Battle of Gettysburg raged in and around the town.

Little Round Top: The smaller of two rocky hills which sits south along Cemetery Ridge. On July 2nd General Meade ordered the 3rd Corp, under the command of General Dan Sickles to occupy the high ground south of Cemetery Hill (which included Little Round Top). Sickles, disobeying direct orders, moved his Corp forward and took position at the base of the bluff. Around 4pm, with Longstreet’s assault underway, Meade learned of Sickle’s insubordination and quickly called on elements of the fifth Corp to occupy Little Round Top, which they did just as the Confederates approached. Despite the strong Confederate onslaught on July 2nd, the elements of the 5th Corp successfully defended the hill.

McPherson’s Ridge: Ridge line west of Gettysburg along which Cavalry General John Buford positioned his dismounted cavalry in an attempt to prevent the Confederates from taking the town of Gettysburg and advantageous topography which surrounded it.

“Pickett’s Charge”: Likely the most infamous episode during the Battle of Gettysburg, “Pickett’s Charge” provided General George Pickett with his first real opportunity to prove himself as a division commander. Commanding the freshest division - totaling roughly 13,000 men - within the Army of Northern Virginia, General Robert E. Lee entrusted him with spearheading the assault against the Union center along Cemetery Ridge. The aftermath of the failed assault left Pickett’s division devastated. Pickett’s division suffered over 50% casualties and lost most of its brigadier generals and regimental commanders, in addition to countless other officers. From the impact and magnitude of this episode, Pickett would never recover.

Seminary Ridge: Ridge line southwest of the town of Gettysburg along which the Army of Northern Virginia positioned itself after July 1st. Seminary Ridge served as the point from which all Confederate attacks were launched on July 2nd – 3rd.

Key Figures:

Lewis Armistead: Virginia-born brigadier general in Pickett’s division. Armistead is the only officer in Pickett’s division to have successfully broken through the Union lines on July 3rd. Leading the 9th Virginia Regiment over the wall, Armistead and his men were able to briefly capture an artillery piece, before he was mortally wounded.

John Buford: Kentucky-born cavalry officer who successfully held-off early Confederate assaults on July 1st. His stalwart defense of Gettysburg allowed elements of the Union 1st Corp to arrive to prevent the Army of Northern Virginia from gaining the high ground in the vicinity of Gettysburg. 

Richard S. Ewell: Promoted to Corp commander before the Battle of Gettysburg, the Virginia-born Ewell, in addition to Longstreet, also faced criticism following the battle. In the aftermath of the engagements on July 1st, Ewell missed an opportunity to order his troops to the peak of Culp’s Hill. Earlier in the day, Lee had ordered his lieutenant to take the hill, “if practicable.” As a result of Ewell’s lack of initiative, the Federals occupied the Hill and Ewell was later unable to reclaim it on July 2nd and 3rd.

Winfield Scott Hancock: Pennsylvania-born commander of the Army of the Potomac’s II Corp. during the Battle of Gettysburg. Hancock’s II Corp was positioned along Cemetery Ridge and thus bore the brunt of Pickett’s Charge on July 3rd. During the evening of July 1st, Hancock arrived to the battlefield and acted as commanding officer in General Meade’s absence. Hancock deemed the terrain around Gettysburg strong and immediately began entrenching the high ground. Though wounded during the battle with a bullet struck him in his thigh, he would recover and later win accolades from his soldiers and Congress for his noteworthy performance at Gettysburg. 

Robert E. Lee: Virginia-born commander of the Army of Northern Virginia during the Battle of Gettysburg. Having experienced a string of military victories prior to the battle, Lee’s actions at Gettysburg proved inspired by the notion that his army was invincible and if properly led, could achieve anything. Lee’s strategic successes on July 1st met with strategic failure in the two days thereafter. Despite pleas from Longstreet on July 2nd not to attack Little Round Top, but to swing around to the bigger round top further south, Lee had made up his mind and would not change his strategy as scouts had told him earlier in the day that Little Round Top was undefended. Additionally, Longstreet’s plea that Lee’s army reposition itself between the Army of the Potomac and Washington on July 3rd, met with similar results. Many have speculated the reasons behind Lee’s decisions during the battle of Gettysburg; some have cited health problems such as angina while others have cited the dominance of a superiority complex. Regardless, his strategic decisions proved grave for the Army of Northern Virginia.

James Longstreet: South Carolina-born Corp commander in the Army of Northern Virginia. Memoirs from the war suggest that Gettysburg proved one of the darkest moments in Longstreet’s career as an officer. Lee conducted the assaults on July 2nd and 3rd almost entirely with troops from Longstreet’s Corp. Longstreet continued his faithful service following the battle and participated in engagements such as Chattanooga and Chickamauga in the Western Theatre. Following the war, Southerners fiercely chastised Longstreet when he dared to criticize Lee’s decisions at Gettysburg.  

George G. Meade: Pennsylvania-born commander of the Army of the Potomac during the Battle of Gettysburg. Following the resignation of “Fighting” Joe Hooker in June, Meade assumed command of the Army of the Potomac and continued following Lee’s army northward into Pennsylvania. A generally quick-tempered man, Meade’s name was unknown to most throughout the army, despite his high rank and reputation as a gentleman soldier. Meade’s first order of business upon taking command was to consolidate his army around Frederick, Maryland. From Frederick, on June 30th Meade ordered his army northward, in a fanning motion toward Pennsylvania as he believed it provided the best potential defense of Baltimore and Washington D.C. During much of the early action on July 1st, Meade was not present. In his stead, he gave temporary command to Winfield Scott Hancock who began developing the defensive position upon Cemetery Ridge in the evening of July 1st. When Meade finally arrived on the battlefield, his continued amassing of forces along Cemetery Ridge coalesced into a “fish hook” formation which allowed him to successfully move troops from one front to another. Following the battle, President Abraham Lincoln asked General Meade to pursue Lee’s retreating army, but Gettysburg also left the Army of the Potomac with high casualties.

George Pickett: Virginia-born division commander within General James Longstreet’s Corp. Arrived during the night of July 2, thus having the freshest division in the entire Army of Northern Virginia. Lee entrusted Pickett with spearheading the attack on July 3rd, which would later bear his name. 

John F. Reynolds: Pennsylvania-born Corp commander in the Army of the Potomac. After the Battle of Chancellorsville in May of 1863 and the resignation of General Joseph Hooker as overall commander of the Army of the Potomac, President Abraham Lincoln supposedly offered Reynolds the position of overall commander. Reynolds respectfully declined as he believed Washington would second-guess his military decisions. Reynolds’ supreme moment came on July 1st when contingents of his I Corp arrived on the battlefield to reinforce the exhausted dismounted Cavalry under the command of John Buford. Shortly after Reynolds’ arrival on the battlefield, he was mortally wounded when a bullet from a Confederate sharpshooter struck him in the back of the head.

Dan Sickles: New York-born commander of the Army of the Potomac’s III Corp. during the Battle of Gettysburg. Disobeying direct orders, Sickles ordered his III Corp., positioned next to the II Corp. along Cemetery Ridge, to advance to a slightly higher piece of land on July 2nd. When Meade learned of Sickles’ insubordination, he confronted him, asking why he had advanced so far ahead. Sickles responded by saying that he had found the area to which had advanced slightly more elevated, but that he would withdrawal to his original position. Meade responded that it was too late, a Confederate attack was imminent and that a retreat would put the III Corp. in even greater danger. During the fighting on July 2nd, Sickle’s received a wound when a Confederate cannon ball tore his leg off. Some historians, such as Stephen W. Sears have argued that Sickle’s decision meant near disaster for the Army of the Potomac, while others such as John Keegan and James McPherson have argued otherwise.


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