Commonwealth Museum

From the Wikipedia page on the Massachusetts Archives

The Archives operates the Commonwealth Museum to educate and display some of its collections of important documents about state and national history. The main permanent exhibit is entitled "The Massachusetts Experiment in Democracy: 1620–Today", and traces the Massachusetts experience through the Colonial, Revolutionary, Federal, and 19th century reform periods. The sub-theme, “Tracing our Roots,” tells the story of four representative Massachusetts families of Native American, English, African-American and Irish heritage. The museum also features changing exhibits of state history from its collections. Admission is free.