Rosaryville State Park in Maryland blends outdoor recreation with the long history of the Mount Airy estate, centered on a restored mansion begun in 1751 by Benedict Swingate Calvert. The property had earlier served as a hunting lodge for the Calvert family and grew into a large plantation worked by more than 150 enslaved people. It was closely tied to prominent early American families through the 1774 marriage of Eleanor Calvert and John Parke Custis and the 1781 birth there of George Washington Parke Custis. After passing out of Calvert ownership, suffering a 1931 fire, and later restoration, the estate became part of the state park established in the 1970s.