Leonardtown's Old Jail Museum was first built in 1858 and completely rebuilt on the same spot in 1878. Today, it is the headquarters for St Mary's County Historical Society. Various artifacts from the county are displayed in the building, which still looks as it did during its lifetime (1876-1942) as a jail. The first floor was where the keeper and his family lived. The second floor had cells for women, men, and African Americans. The building is an official Underground Railroad Network to Freedom Site. Just outside the museum in is a canon from The Ark, one of the two ships that brought colonists to Maryland in the 17th century.