The Old State House is a historic building in Boston, Massachusetts, at the intersection of Washington and State Streets. Built in 1713, it was the seat of the Massachusetts General Court until 1798, and is one of the oldest public buildings in the United States. One of the landmarks on Boston's Freedom Trail, it is the oldest surviving public building in Boston, and now serves as a history museum operated by the Bostonian Society. It was designated a National Historic Landmark in 1960.