 Many of makeshift trenches and blockhouses that resulted would later be renovated and expanded into permanent defenses surrounding Fort Corcoran.On July 23, President Abraham Lincoln and Secretary of State William Seward visited Fort Corcoran in an effort to revive morale after the defeat at Bull Run.On July 26, 1861, five days after Bull Run, Maj. Gen. George B. McClellan was named commander of the military district of Washington and the Army of the Potomac.