The monument to the Army of the Potomac is on Hancock Avenue (Tour map: Hancock Avenue at The Angle) and a marker south of the Leister House on Taneytown Road.

Monument to the Army of the Potomac at Gettysburg

From the monument:

Army of the Potomac 
Major General George G. Meade

The Army consisted of Eight Corps

First Corps Major General John F Reynolds
Major General Abner Doubleday
Major General John Newton

Second Corps Major General Winfield S. Hancock
Brigadier General John Gibbon

Third Corps Major General Daniel E. Sickles
Major General David B. Birney

Fifth Corps Major General George Sykes

Sixth Corps Major General John Sedgwick

Eleventh Corps Major General Oliver O. Howard

Twelfth Corps Major General Henry W. Slocum
Brigadier General Alpheus S. Williams

Cavalry Corps Major General Alfred Pleasonton

Reserve Artillery Brigadier General Robert O. Tyler

July 1. The First and Eleventh Corps arrived, and were engaged north, and, west of Gettysburg,and fell back to Cemetery Hill in rear of the town. The Twelfth Corps and a large part of the Third Corps arrived at the close of the day.

July 2 . The remainder of the Third Corps and theFifth and Second Corps arrived in the morning. TheSixth Corps late afternoon. The Third Corps having advanced was attacked by Longstreet’s Confederate Corps and Anderson’s Division of Hill’s Corps. The Fifth Corps, and the First Division of the Second Corps going to the support of the Third Corps an engagement ensued until nightfall when the Union forces had been driven back from their advanced position and the Confederates repulsed.

July 3. The Twelfth Corps having by order vacated a large part of its line on Culps Hill, on the night of the 2d and Johnson’s Division of Ewell’s Corps having occupied the works. The Twelfth Corps in the morning attacked and regained the lines it had previously vacated. Hill’s Corps and Pickett’s Division of Longstreets Corps in the afternoon attacked the line of the Second Corps and were repulsed with great Loss. Stuart’s Confederate Cavalry in the afternoon attacked the Second Cavalry Division and the Second Brigade Third Cavalry Division and was repulsed.

Monument to Major General George Meade's Headquarters at Gettysburg

 From the marker:

Headquarters of
Major General
George G. Meade
Army of the Potomac