A Union column consisting of elements of the VI and XIX Corps pursued Maj. Gen. Jubal Early’s army as it withdrew from Washington, D.C. in July, 1864. On July 17, Union cavalry following Early passed through Snickers Gap and attempted to force a crossing of the Shenandoah River at Castleman’s Ferry. The next morning, the vanguard of the Union infantry moved through the gap. Col. Joseph Thoburn led a division downstream to cross the river. Early’s three nearby infantry divisions moved to defend the fords and block the Yankees. In the afternoon, the Confederates attacked and shattered Thoburn’s right flank on the Cool Spring Farm. Thoburn's men made a stand behind a stone wall at the river’s edge and beat off three attacks until darkness enabled them to withdraw. The battle delayed Union pursuit of Early into the Valley several days.