United States. Army. 138th Pennsylvania Infantry Regiment diary
The 138th Pennsylvania Infantry Regiment, containing 10 companies, was one of the first regiments to organize after President Abraham Lincoln's call for volunteers. The regiment mustered at Harrisburg, Pennsylvania, on August 26, 1862, under Charles L.K. Sumwalt, and spent much of 1863 in Maryland and northern Virginia, pursuing Confederate General Robert E. Lee. They first saw action in the Battle of Wapping Heights on July 23, 1863, and served as part of the Army of the Potomac and, later, the Army of the Shenandoah. The regiment was mustered out on June 23, 1865.