On Friday, May 3, 1861, the U.S. War Department created the Department of the Ohio, organizing the troops being raised in the Northern states near the Ohio River -- Ohio, Indiana, and Illinois. George McClellan, a West Point graduate and Mexican War veteran, was named as its first commander.
Also on this date, in Washington, Lincoln expanded his call for troops. He had called for 75,000 militia in his war proclamation on April 15. Now he was calling for 42,000 more. He also directed that the regular army by increased by over 22,000 and the Navy by 18,000. As Congress was not yet in session, he did this without their approval.
In Missouri, Governor Claiborne Jackson addressed the state legislature which he had called into special session. Jackson, who was toiling to take the state (and the St. Louis Arsenal) out of the Union, told the legislators that Missouri should remain neutral for the present, but should start arming for its own defense.