Hennessy's was an American department store, founded by Daniel Hennessy of Butte, Montana in 1898. Stores opened throughout Montana. In the 1970s, the company was acquired by Mercantile Stores and the headquarters moved to Billings, Montana. When Mercantile Stores was acquired by Dillard's in 1998, the 100-year-old name was retired in favor for Dillard's.