The Battle of Boonville on June 17, 1861, was one of the earliest battles of the Civil War. With the federal victory, the Union gained control of the Missouri River Valley and forced the pro-Confederate Missouri State Guard (MSG) into the southwestern corner of the state, cutting the latter off from recruits north of the Missouri River. The Battle of Boonville persuaded Confederate forces in northwest Arkansas to come to the aid of the MSG at the subsequent Battle of Wilson’s Creek and drove Governor Claiborne Fox Jackson and his government closer to secession.