The Island has a diverse history of human habitation. Remnants from Native American occupancy indicate that the Island was used as a seasonal fishing village. In the 1600’s the site was named “My Lord’s Island” when King Charles I granted it to Lord Baltimore.
One owner, a sea captain, called it “Barbadoes” after his childhood home. In the 1790s, John Mason, son of George Mason IV (author of Virginia’s Bill of Rights), built a brick mansion and cultivated gardens. The Island was known as “Mason’s Island” during this period. During the Civil War, the site served as a training area for the Union Army, including the “First U.S. Colored Troops.” For years afterwards, the Island was used in different capacities, including as a picnic resort, an athletic club and a boathouse until Washington Gas Light Company purchased the property in 1913.