The headquarters marker for Major General Daniel E. Sickles, commander of the Third Corps, Army of the Potomac.
Dedicated: June 1913.
Location: Located on South side of Unites States Avenue near Trostle House.
Description: One of ten Civil War US Headquarter Markers in the Park. Consists of cast iron cannon tube, 4.5-inch rifled siege gun, mounted on a granite base. Erected by the Gettysburg National Parks Commission. Designed by Emmor B. Cope of the War Department. Rough-hewn, coursed, 3 part base, 3’2″sq, 2’7″H. Cannon tube mounted upright on base. Overall 10’6″H. Bronze inscription tablet on North face.
Army of the Potomac
3d. Corps Headquarters
Daniel E. Sickles
July 1. 2. 1863