Croswell Opera House in Adrian, MI, is the oldest continuously running theater in Michigan, and among the oldest in the U.S. The theater and the adjoining hall were designated as a Michigan Historic Site on Mar. 2, 1976, and later added to the National Register of Historic Places as the Adrian Union Hall-Croswell Opera House on Apr. 18, 1985. People who spoke at the Croswell in its early days included Frederick Douglass and Susan B. Anthony.