The Battle of Chalk Bluff was a land battle of the American Civil War that took place in Clay County, Arkansas, and Dunklin County, Missouri, on May 1 and May 2, 1863. Brig. Gen. William Vandever, commanding the 2nd Division of the Union Army of the Frontier, was repulsed in an attempt to prevent Confederate cavalry under Brig. Gen. John S. Marmaduke from crossing the St. Francis River.