In the Civil War, Missouri was a border state that sent men, armies, generals, and supplies to both opposing sides, had its star on both flags, had separate governments representing each side, and endured a neighbor-against-neighbor intrastate war within the larger national war. The first major Civil War battle west of the Mississippi River was on August 10, 1861 at Wilson's Creek, Missouri, whereas the largest battle in the war west of the Mississippi River was the Battle of Westport at Kansas City in 1864.