Official Name: State of Wisconsin. Organized as a territory/republic: July 4, 1836. Entered Union (rank): May 29, 1848 (30) Present constitution adopted: 1848. State Area Codes: 262, 414, 608, 715, 920. Nickname: Badger State. Origin of name: Wisconsin is the English spelling of a French misinterpretation of the name Meskonsing.