General Fitz John Porter

Union general Fitz John Porter, head of the Army of the Potomacs Fifth Corps, ordered his soldiers to cross the Potomac River and attack the Confederates during the two-day Battle of Shepherdstown in September 1862. Initial success on the shore was met with strong resistance in the town itself, so the Fifth Corps retreated back to the Maryland side of the river, where it remained until the end of October, allowing Robert E. Lees Army of Northern Virginia to escape into the Shenandoah Valley.