Twelfth Corps

At Gettysburg, the Army of the Potomac's Twelfth Corps, commanded by Major General Henry W. Slocum, included the First Division under Brigadier Generals Alpheus S. Williams and Thomas H. Ruger, the Second Division under Brigadier General John W. Geary, an artillery brigade under Lieutenant Edward D. Muhlenberg, and a provost guard from the Tenth Maine. On July 1 the corps marched from near Littlestown to Two Taverns and, after hearing that the 1st and 11th Corps were engaged at Gettysburg, advanced on the Baltimore Pike, with Williams's Division taking position east of Rock Creek and Geary's Division extending to the summit of Little Round Top on the left of the Union line. On July 2 the corps took position on the right of the 1st Corps from the top of Culp's Hill southeasterly across the low meadow into McAllister's Woods, but later, except for Greene's Brigade, was withdrawn to support the army's left; that night Johnson's Confederate Division advanced under cover of darkness and occupied the works on the corps line to the right of Greene's Brigade, and about midnight the corps returned and formed in front of the occupied works. Before 1 a.m. on July 3, the corps artillery and Rigby's Maryland Battery from the Reserve Artillery, twenty-six guns in all, were placed to command Johnson's line, and at daylight they opened fire, under cover of which the infantry advanced, attacked the Confederate position, and after a seven-hour contest recaptured the works, taking many prisoners and more than 5,000 small arms; that afternoon the corps stood ready to move. On July 4 Slocum advanced in the morning with a detachment of Ruger's Division and a battery and found that the Confederates in front had retired. The corps suffered casualties of 18 officers and 186 men killed, 43 officers and 769 men wounded, and 2 officers and 64 men captured or missing, for a total of 1082.

Gettysburg, Pennsylvania · United States