Organized under General Orders No. 101, March 13, 1862, by which the First, Second, and Third Corps were also created. It was formed by the divisions of Couch, Smith, and Casey, with General E. D. Keyes in command of the corps. The returns for March 31, 1862, show that the Fourth Corps then numbered, in the aggregate, 37,910, with 60 pieces of artillery; of this number, there were 32,919 present for duty. The corps moved to the Peninsula in March, 1862, with General McClellan's Army, taking part in the siege operations at Yorktown, and participating in the battle of Williamsburg, where it sustained a slight loss only.
On May 18th, General Wm. F. Smith's Division was detached and assigned to the newly formed Sixth Corps, leaving the Fourth Corps to consist of the divisions of Generals Couch and Casey. After this reduction, it numbered on May 31st, 25,317 present and absent, with 17,132 present for duty; the artillery numbered 38 guns.
At the battle of Seven Pines (Fair Oaks) the full force of the Confederate attack was directed on an advanced position held by Casey's Division, which stood its ground for an hour, inflicting a severe loss on the enemy, and not retiring until sufficient supports had arrived to save the day. Couch's Division was also hotly engaged, the losses in the corps aggregating 384 killed, 1,747 wounded, and 466 missing; total, 2,597 out of less than 12,000 engaged. Over half the loss at Fair Oaks fell on the Fourth Corps.
During the Seven Days Battle, the corps guarded the trains during their withdrawal to the new base of supplies, but Couch's Division took a prominent part in the battle of Malvern Hill, losing over 600, killed or wounded there.
When the army was ordered to abandon its position before Richmond, the Fourth Corps was divided. Couch's (1st) Division accompanied the Army of the Potomac on the Maryland campaign, some of the regiments becoming slightly engaged at Antietam. After that battle, Couch's Division was transferred, entire, to the Sixth Corps, becoming the Third Division of that corps, with General John Newton commanding the division. General Couch was promoted to the command of the Second Corps.
In the meantime, Peck's (2d) Division of the Fourth Corps was ordered to remain on the Peninsula, from whence it went, after a few months stay, to Suffolk, Va. The Fourth Corps was officially discontinued in August, 1862, and its divisions were never reunited.
|Siege Of Yorktown||Lee's Mills|
|Fair Oaks||Oak Grove|
|Seven Days Battle||Malvern Hill|