The building was constructed as the City's Library in 1902 through the Carnegie Foundation and is listed on the National Register of Historic Places.  In 1968, the Janesville Public Library out grew the building and moved.  Parts of the building served: Janesville Little Theater, Leisure Services and the Senior Center.  in 1981, the building exclusively became the Janesville Senior Center.

The Tom Jeffris and the Jeffris Family Foundation offered a generous donation of $210,000 to expand and modernize the building.  The project included renovation of the first two floors of the existing building, construction of a two-story 6,000 sq. ft. addition, and parking improvement.  The foundation's assistance ensured that the building addition could be done to preserve the building's architecture.  The renovation was completed in January 2000.

A community-led fundraising effort was done to buy furnishings for the Center.  They exceeded their $100,000 goal.  A donor plaque hangs in the front entrance of the Senior Center.