Given command of the Department of Ohio at the beginning of the American Civil War, McClellan secured a series of minor victories in West Virginia, and in November 1861 succeeded Winfield Scott as general-in-chief of the Union (Northern) armies. While he lost this post in March 1862, he retained command of the Army of the Potomac. His attempt to capture Richmond in the Peninsular campaign proceeded too slowly and was then ruined by counter-attacks from forces of the Confederacy in the Seven Days’ battles. He checked Lee at Antietam, but missed the opportunity to destroy his opponent and bring the war to an end, and was subsequently removed from command. McClellan unsuccessfully ran as the Democrat presidential candidate against Lincoln in 1864.