Engaged with other Union troops in Major-General Ambrose Burnside's "Mud March" in January 1863, Elliot and his regiment were then assigned to picket duties between Falmouth and Port Conway until late April when they were ordered to duty in the Chancellorsville Campaign. After participating in Stoneman's 1863 raid, they fought in the Battle of Aldie (June 17). Reassigned to the Gettysburg Campaign, they fought in the Battle of Gettysburg (July 1-3), and pursued the enemy from Pennsylvania back into Maryland and Virginia throughout the late summer and early fall. After fighting next in the Battle of Culpeper Court House (September 13), they engaged in the Bristoe Campaign (October 9-22) and the Mine Run Campaign (November 26-December 2).