Department of the Monongahela
The Department of the Monongahela was a military department created by the United States War Department during the Gettysburg campaign of the American Civil War. == History == On June 9, 1863, President Abraham Lincoln, responding to Robert E. Lee's impending invasion of Maryland and Pennsylvania, called for 100,000 volunteers from those two states, as well as West Virginia and Ohio, to help repel the invasion, with only about 33,000 recruits answering his call.
Source: Wikipedia — Department of the Monongahela (CC BY-SA 4.0)