The museum's collection includes over 100 paintings by Hoosier Group, Indiana Regionalism artists as well as ceramics, antique furniture and decorative items.

The formation of the Haan Mansion Museum of Indiana Art was announced in September 2013 when it also opened for monthly public tours.

[2] The front door and entry way as well as interior architectural features were taken from the 1760 Hubbard Slater Mansion and incorporated in the design of the Connecticut Building.

This includes works by all five of the group's members TC Steele, Richard Gruelle, William Forsyth, J. Ottis Adams and Otto Stark.

Many artists from Brown County Art Colony are represented in Haans' collection, including Ada Walter Shulz.

A Swiss made cylindrical music box featuring drums, bells, castanets, organ and flute sections is one of the highlights of the museum.