Thursday, June 25, 1863
The Second Corps left Thoroughfare Gap this morning after a well-needed four-day rest. Confederate Cavalry General James Ewell Brown (J.E.B.) Stuart, on one of his famous raids, attacked the rear of the Union Army as they departed from Thoroughfare Gap. As the Second Corps reached Haymarket, a short distance from Thoroughfare Gap, Stuart fired upon the Second Division, of which the Twentieth Massachusetts was a part, exacting casualties. Heavy rains halted the advance of the Second Corps as they made evening camp during a deluge.1
1George A. Bruce, The Twentieth Regiment of Massachusetts Volunteer Infantry 1861 - 1865 (Cambridge, Massachusetts: The Riverside Press, 1906), 263.