|Major General Robert Patterson|
The Department of Pennsylvania was established April 27th 1861, and covered the states of Delaware, Maryland, and Pennsylvania. The Department was under the command of Union Major General Robert Patterson. The force was made up of mostly of three month troops from New York, Pennsylvania and Wisconsin. The men of the Department achieved an early tactical victory at the Battle of Hoke’s Run July 2nd 1861. Patterson and his Department of Pennsylvania was held as indirectly contributing to the Union loss at the First Battle of Bull Run on July 21st 1861.
The Department was disbanded August 24th 1861. Any of the regiments whose terms of enlistments weren’t up, and their commanders were merged into the Department of the Shenandoah under the command of Union Major General Nathaniel P Banks. Patterson received an honorable discharge from the Union Army July 27th 1861.