Union Heroes of the Battle of Gettysburg, the Corps Commanders of the Army of the Potomac

General George G. Meade. Image Source: Library of Congress.

The Battle of Gettysburg was fought from July 1–3, 1863 in and around the town of Gettysburg, Pennsylvania. Over the course of the three days, both Union and Confederate armies suffered more than a combined 50,000 casualties, making it the bloodiest single battle of the entire war. Despite the horrible toll it took on American lives, Union forces prevailed, led by General George G. Meade, his Corps Commanders, and their Division Commanders.

Lincoln Puts General George G. Meade in Command of the Army of the Potomac

Following the loss at Chancellorsville, General Joseph Hooker resigned from his command of the Army of the Potomac. On June 27, 1863, President Abraham Lincoln placed General George G. Meade in command. 

Abraham Lincoln, Portrait, Gardner
President Abraham Lincoln. Image Source: Wikipedia.

Only six days later, Meade led the army to victory over General Robert E. Lee and the Army of Northern Virginia in what many believe was one of the most significant turning points of the Civil War. 

Despite the victory at Gettysburg, President Lincoln criticized Meade for not pursuing Lee’s army as it retreated to Virginia. Nevertheless, officials promoted Meade to Brigadier General in the Regular Army and he received the Thanks of Congress on January 28, 1864.

1st Corps Commanders at Gettysburg

John F. Reynolds

At the start of the battle, Major General John F. Reynolds was in command, until he was shot and killed on the battlefield on July 1. 

John F Reynolds, Portrait
General John F. Reynolds (USA). Image Source: Library of Congress.

When Meade assumed command of the Army of the Potomac, he placed Reynolds in charge of the army’s left wing. During the Battle of Gettysburg, Reynolds arrived on the field in mid-morning on July 1, 1863, and began deploying his troops. At roughly 10:15, while Reynolds was positioning soldiers at Herbst Woods, a musket ball struck him in the back of the neck, killing him instantly. 

The 1st Corps Divisions were commanded by Brigadier General James S. Wadsworth, Brigadier General John C. Robinson, and Major General Abner Doubleday.

Abner Doubleday

Major General Abner Doubleday, who was commanding the 3rd Division, assumed command of the entire corps for the rest of the day.

General Abner Doubleday, Civil War, USA
General Abner Doubleday (USA). Image Source: Library of Congress.

Facing increasingly intense pressure as the Army of Northern Virginia began arriving on the scene, Doubleday’s soldiers held their positions early in the day but gave ground during the afternoon. Between 4 and 5 p.m. they fell back through the town and re-formed their lines on the heights of Cemetery Hill. Incorrectly believing that the 1st Corps had collapsed, leading to the break of the Union lines, a displeased Meade replaced Doubleday as 1st Corps commander with Major General John Newton, an officer junior in rank to Doubleday.

John Newton

After Doubleday’s removal, Major General John Newton commanded the 1st Corps for the remainder of the battle.

2nd Corps Commanders at Gettysburg

Winfield Scott Hancock

During the Battle of Gettysburg, Major General Winfield Scott Hancock made the crucial command decision to defend Cemetery Ridge, withstanding Major General George Pickett’s unsuccessful charge. Hancock was seriously injured in the thigh during the battle and suffered lingering effects for the rest of his life.

Winfield Scott Hancock, Civil War General
General Winfield Scott Hancock (USA). Image Source: Library of Congress.

2nd Corps Division Commanders

The 2nd Corps Divisions were commanded by Brigadier General John C. Caldwell, Brigadier General John Gibbon, and Brigadier General Alexander Hays.

3rd Corps Commanders at Gettysburg

Daniel E. Sickles

Major General Daniel E. Sickles openly disobeyed Meade’s orders during the battle, nearly leading to disaster. When Sickles arrived at Gettysburg on July 2, Meade ordered him to position his corps along the lower section of Cemetery Ridge, between Winfield S. Hancock’s 2nd Corps and a small hill known as Little Round Top.

Believing that Meade’s orders stretched his corps too thinly, Sickles failed to secure Little Round Top. Then, believing that the ground to his front was more defensible, Sickles moved his corps forward one half-mile without Meade’s approval.

The unauthorized advance left Hancock’s flank unguarded. It also created a salient —  a bulge — in the Union line, exposing the 3rd Corps corps to assault from two sides. 

When Meade arrived on the scene, he berated Sickles for ignoring his orders. Sickles offered to withdraw from his advanced position, but his proposal was too late. Confederate Lieutenant General James Longstreet had recognized the mistake and attacked. 

Longstreet’s soldiers overwhelmed the 3rd Corps, inflicting over 4,000 casualties among the roughly 10,000 Union soldiers engaged.

During the fighting, a Confederate cannonball struck Sickles’ right leg, forcing its amputation and the evacuation of the injured general from the field.

General Daniel Sickles (center) visiting Gettysburg in 1886. Image Source: Library of Congress.

3rd Corps Division Commanders

The 3rd Corps Divisions were commanded by Major General David B. Birney and Major General Andrew A. Humphreys.

5th Corps Commanders at Gettysburg

George Sykes

Major General George Sykes and the 5th Corps arrived at Gettysburg on July 2, 1863, the second day of the battle. Meade ordered Sykes toward the left of the army to support the 3rd Corps, which was under assault by 14,000 Confederates commanded by Lieutenant General James Longstreet. 

When Meade discovered that a small hill known as Little Round Top was undefended, he ordered Sykes to occupy the hill and to “hold at all hazards.” While a brigade of Sykes’ command led by Colonel Strong Vincent did so, Sykes sent reinforcements to fill holes in the 3rd Corps’ lines in the adjacent Wheatfield. 

When the fighting subsided at the end of the day, the Federals were able to withstand the attack and kept Longstreet from flanking the Union army. Sykes’ performance at Gettysburg marked the height of his career as a combat leader.

5th Corps Division Commanders

The 5th Corps Divisions were commanded by Brigadier General James Barnes, Brigadier General Romeyn B. Ayres, and Brigadier General Samuel W. Crawford.

6th Corps Commanders at Gettysburg

John Sedgwick

At the Battle of Gettysburg (July 1-3, 1863), Major General John Sedgwick and the 6th Corps were far from the initial fighting. After a forced march of twenty hours, his men reached the fighting on July 2. Because of exhaustion, most of the 6th Corps stood in reserve during the battle.

6th Corps Division Commanders

The 6th Corps Divisions were commanded by Brigadier General Horatio G. Wright, Brigadier General Albion P. Howe, and Major General John Newton. Newton was promoted during the battle and took command of the 1st Corps.

11th Corps Commanders at Gettysburg

Oliver O. Howard

Major General Oliver O. Howard commanded the 11th Corps during the battle. 

General Oliver Otis Howard, Civil War
General Oliver O. Howard. Image Source: Library of Congress.

On the first day of battle, Major General Jubal Early’s division exploited a bulge in Howard’s defensive line north of town. Early’s attack sent the 11th Corps fleeing back through Gettysburg to the high ground on Cemetery Hill south of town. Howard’s men recovered, and Early’s follow-up assault the next day failed to dislodge them from their new position.

Union artillery fire from Cemetery Hill on the third day of battle contributed to the failed Confederate assault — popularly known as Pickett’s Charge — on Cemetery Ridge. 

Some historians credit Major General Winfield Scott Hancock with the decision to defend and hold Cemetery Hill. Nonetheless, on January 28, 1864, Howard received the Thanks of Congress for the decision.

11th Corps Division Commanders

The 11th Corps Divisions were commanded by Brigadier General Francis C. Barlow, Brigadier General Adolph von Steinwehr, and Major General Carl Schurz.

12th Corps Commanders at Gettysburg

Henry Slocum

Major General Henry Slocum made decisions on the first day of the battle that left led to criticism from his peers and, later, from historians.

While marching the 12th Corps toward Gettysburg, Slocum stopped at a prearranged site roughly five miles southeast of town on the morning of July 1, despite claims from subordinate officers that there was clear evidence that a battle was being waged.

Starting at 1:00 p.m., Slocum received several requests from Major General Oliver O. Howard to advance his 12th Corps to Gettysburg to support the 11th Corps, which was heavily engaged. Slocum wavered and did not proceed toward Gettysburg until late in the afternoon, even though his arrival would have made him the senior general on the battlefield. 

As a result, Slocum did not reach Gettysburg and take control until nearly 6:00 p.m. — after the 11th Corps had suffered heavy losses. His sluggish behavior later earned Slocum the derogatory nickname, “Slow Come.”

Slocum commanded the troops at Gettysburg until approximately midnight when Meade arrived. During the rest of the battle, Slocum and his men performed well. 

On the afternoon of July 2, when Meade ordered Slocum to deploy all the 12th Corps to the Union right, Slocum convinced Meade to allow him to keep one brigade on Culp’s Hill. The decision later proved to be beneficial, as Brigadier General George S. Greene’s brigade withstood several spirited Confederate assaults on the strategic elevation.

12th Corps Division Commanders

The 12th Corps Divisions were commanded by Brigadier General Alpheus S. Williams and Brigadier General John W. Geary.

Cavalry Corps Commanders at Gettysburg

Alfred Pleasonton

General Meade was cautious of Major General Alfred Pleasonton, who commanded the Cavalry Corps at Gettysburg. As a result, Meade oversaw most of the cavalry’s actions directly, depriving Pleasonton of any opportunity to distinguish himself during the pivotal battle. Despite his lack of action, officials promoted Pleasonton to Colonel in the Regular Army effective July 2, for gallant and meritorious conduct in the Battle of Gettysburg.

General Alfred Pleasonton, USA, Civil War
General Alfred Pleasonton. Image Source: Library of Congress.

Cavalry Corps Division Commanders

The Cavalry Corps Divisions were commanded by Brigadier General John Buford, Brigadier General David McMurtrie Gregg, and Brigadier General Hugh Judson Kilpatrick.