The Battle of Westport was one of the largest battles west of the Mississippi River, with over 30,000 troops involved. The Union victory put an end to Price's campaign for Missouri, and the battle has accordingly been referred to as "The Gettysburg of the West". Curtis wrote to Henry W. Halleck after the battle that "the victory at Westport was most decisive." This greatly contested border state was now firmly under Union control, and would remain so until the end of the war.