Arkansas was admitted to the Union on 15 June 1836 as the 25th state. The name is derived from a word used by the Quapaw Indians to designate the territory that now comprises the state. The Jesuit missionary and explorer, Pere Jacques Marquette and his confreres recorded the term as Alkansas and as Akamsea. No meaning for the Algonquin word itself has been found.
The second Arkansas—a single-turreted, "New-Navy" monitor commissioned on 28 October 1902—was renamed Ozark (q.v.) on 2 March 1909.