an old Regular Army veteran with 40 years of service. Its division and brigade organization were the same as at Cedar Mountain; Brig. Gen. George S. Greene had succeeded Augur in the command of the 2nd Division. Its depleted columns had been strengthened by the accession of five new regiments of volunteers fresh from the North, three of which were composed of Pennsylvanians enlisted for nine months only. The corps now numbered 12,300 present for duty, including the non-combatants; it contained 22 regiments of infantry and three batteries of light artillery. It was the smallest corps in the army. It was not engaged at South Mountain, although it marched in plain view of the battle that was raging on the mountain's side, ahead of its dusty columns. At the Battle of Antietam, it entered the fight early in the morning, and carried a position near, and in front of, the Dunker Church. General Mansfield fell, mortally wounded, while deploying his columns, and the command of the corps during the battle devolved on General Williams. The two divisions lost in this battle, 275 killed, 1,386 wounded, and 85 missing; total, 69 42, out of about 8,000 present in action. The vacancy caused by the death of General Mansfield was filled by the appointment of Maj. Gen. Henry W. Slocum, a division commander of the VI Corps, who had already achieved a brilliant reputation by his services on in the Peninsula Campaign, and at the successful storming of Crampton's Gap. The XII Corps spent the Battle of Fredericksburg at Harper's Ferry and was not involved in that battle. The corps went into winter quarters at Stafford Court House. Chancellorsville and Gettysburg The brunt of the Battle of Chancellorsville fell on the XI and XII Corps; and yet amid all the rout and confusion of that disastrous battle the regiments of the XII Corps moved steadily with unbroken fronts, retiring at the close of the battle without the loss of a color, while the corps artillery, after having been engaged in the close fighting at the Chancellor House, withdrew in good order, taking every gun with them. In this campaign Slocum's troops were the first to cross the Rapidan River, and the last to re-cross the Rappahannock River. The corps at this time contained 30 regiments of infantry, with five batteries of light artillery, numbering in all 19,929 present for duty. Its losses