12th Pennsylvania Infantry Regiment

1861
April 22	Organized at Pittsburg under Colonel David Campbell, Lieutenant Colonel Norton McGiffin and Major Alexander Hays
April 24	Moved to Harrisburg, Pa.
April 25	Reviewed by Governor Curtin and mustered into U.S. service, then immediately moved to York, Pa. by rail as part of Patterson's Deparment of Pennsylvania
May 25	Guard duty on Northern Central Railroad from State line to Baltimore Md. Headquarters at Cockeysville, Md., relieving the 1st Pennsylvania Infantry. Headquarters was at Cockeysville with Companies I and K, the other companies widely scattered until end of enlistment.
August 5	Mustered out