Transported by rail to Washington, D.C. in early October 1861, Sands and his fellow 88th Pennsylvania Volunteers helped to defend the nation's capital through October 12 when they were moved to Alexandria, Virginia and assigned to guard duty, a mission they continued to perform at various duty stations through May 25, 1862 when they were marched to Front Royal, placed on a train, and transported to Manassas, Warrenton and Culpeper. Their first major combat test came in the Battle of Cedar Mountain (August 9), where they served in Brigadier-General Zealous Bates Tower's brigade at the far right of the Union Army commanded by Major General Nathaniel P. Banks. The battle successfully concluded, they were moved to Pony Mountain and Warrenton before engaging in operations near Thoroughfare Gap, Gainesville and Manassas Junction. Commended by General John Pope for their performance in the Second Battle of Bull Run (August 29–30), the 88th Pennsylvanians were then ordered on to Fairfax, Washington and Frederick before participating in the intense combat of the Battle of Antietam (September 17). After re-engaging with the enemy near Bowling Green on December 13, Sands and his regiment were ordered to make camp for the winter at Fletcher's Chapel, where they remained until they were assigned to participate in Major-General Ambrose Burnside's Mud March (mid-January 1863). Returned to winter quarters after the failed operation, they next engaged the enemy at points along the Rappahannock River (April 28), and were then reassigned to Major-General John F. Reynolds’ corps as part of the Gettysburg Campaign. On day one of the Battle of Gettysburg (July 1, 1863), Sands was captured by Confederate troops.