Major General Robert Patterson led Pennsylvania state volunteers and U. S. Regulars into Maryland through Hagerstown and Washington County in June 1861 to retake the captured U. S. Arsenal at Harpers Ferry, but arrived too late. The Confederates torched the arsenal buildings, eluded Patterson and successfully joined the main Rebel army for the battle of First Manassas. Patterson’s army included the famous Fort Sumter Artillery Battery commanded by Abner Doubleday.