Brigadier General William S. Harney, commander of the Department of the West, agrees to a truce with Sterling Price, commander of the Missouri State Guard, to preserve peace in Missouri during the secession crisis. The agreement leaves the Union in control of the St. Louis area, including the federal arsenal, but it leaves the secessionist Price in charge of the Missouri State Guard and most of the rest of the state. Strong Unionists immediately denounce the agreement, and President Lincoln relieves Harney of command. Nathaniel Lyon is placed in command of the Department of the West on May 30, 1861, with an implicit order to keep Missouri in the Union.