McClellan took the army from Washington to the Peninsula of Virginia in an attempt to capture the confederate capital of Richmond.

During this campaign, the regiment fought the "Seven Days Battles" including Gaines Mills and Malvern Hill during its land retreat back to Washington DC.

At this time, September, 1862, General Robert E. Lee invaded Maryland with his Army of Northern Virginia.

McClellan was placed back in command of the army and they caught up with Lee at Antietam Creek in Western Maryland.

They engaged in battle in the early afternoon and charged from the East Woods to the Dunker Church.