Maryland, a slave state with abundant popular support for secession in some areas, remained part of the Union during the American Civil War, due in part to the Union's strategic occupation of the city in 1861. The Union's capital, Washington, in the state of Maryland (geographically if not politically), was well-situated to impede Baltimore and Maryland's communication or commerce with the Confederacy. Baltimore saw the first casualties of the war on April 19, 1861, when Union Soldiers en route from the President Street Station to Camden Yards clashed with a secessionist mob in the Pratt Street riot.