Sunday, June 1, 1862
The Twentieth Massachusetts was not engaged in the morning attack that ended the Battle of Fair Oaks, also known as the Battle of Seven Pines. Units from General Israel Richardson's division of the Second Corps and General Joseph's Hooker's Third Corps encountered and repulsed Confederate units led by James Longstreet and Daniel Harvey Hill. After a two-hour engagement the Confederate forces retreated to Richmond.
The wounding of Confederate General Joseph Johnston at Fair Oaks led to a change in command of the Confederate Army. During the evening General Robert E. Lee assumed leadership of the Army of Northern Virginia.1
1George A. Bruce, The Twentieth Regiment of Massachusetts Volunteer Infantry 1861 - 1865 (Cambridge, Massachusetts: The Riverside Press, 1906), 100. Richard F. Miller, Harvard's Civil War: A History of the Twentieth Massachusetts Volunteer Infantry (Lebanon, New Hampshire: University Press of New England, 2005), 133.