Saturday, May 31, 1862
Confederate General Joseph Johnston ordered an attack on the Army of the Potomac to drive the Union lines away from Richmond. Confederate Generals Daniel Harvey Hill and James Longstreet struck Brigadier General Silas Casey’s division of General Darius Couch’s Fourth Corps, driving the Union line back to the Williamsburg Road nearly one-and-a-half miles from Seven Pines Station.
The Twentieth Massachusetts, in General John Sedgwick’s division, was called to arms at 1:00 PM. They encountered their first obstacle at the Grapevine Bridge, whose structure was compromised from rising water due to heavy rains. Sedgwick's division crossed over the bridge safely before the bridge collapsed. The division confronted the enemy lines with fixed bayonets and successfully repulsed the Confederate attack near Fair Oaks Station.
The Confederates suffered heavy casualties among their officers. Brigadier General Wade Hampton was wounded, J. Johnston Pettigrew was wounded and captured, and Robert H. Hatton was killed. Confederate commander Joseph Johnston was severely wounded.
The casualty list for the Twentieth Massachusetts listed five killed and twenty-three wounded.1
1George A. Bruce, The Twentieth Regiment of Massachusetts Volunteer Infantry 1861 - 1865 (Cambridge, Massachusetts: The Riverside Press, 1906), 90 - 101.