In 1859, the Town of Southborough built five school houses in different parts of town, with the District 5 School house being located at the intersection of Flagg and Deerfoot Roads. In 1894, with the school house at Southborough Centre having fallen into disrepair, the District 5 school house was moved (and extended by ten feet) to replace it. After a new High School was built in 1906, the old school house, now known as the Flagg School, became home to the Southborough Fire Department until 1928. It later served the town’s Tree Department and then the Water Department. In 1998, the building was leased to the Southborough Historical Society, which renovated it. In 2000, it was dedicated as the Southborough Historical Museum.