Now: Known today as Theodore Roosevelt Memorial Island, this 88.5-acre park in the middle of the Potomac is popular with runners, hikers and dog walkers who appreciate its wooded trails and diverse birdlife. Only a hard-to-find sign indicates where John Mason’s posh house once stood; its burned ruins were torn down in the 1930s.
Then: Who wouldn’t want to own a private summer retreat? John, the son of wealthy planter and Founding Father George Mason (proprietor of Gunston Hall in Lorton), inherited this island in 1792. He renamed it Analostan after the Necostins, the same Native American tribe that gave Anacostia its name.
Choosing a site within view of his Georgetown home, he built—with slaves and hired black labor—a Classical Revival-style house of brick and sandstone at the southern end of the island, surrounding it with fruit orchards, trees, shrubs, and culinary and formal gardens. After he married in 1796, John and his wife hosted festive parties on the island for high-profile guests, including Thomas Jefferson, James Madison, James Monroe and Louis-Philippe, the future king of France. Like his friend Jefferson, John was interested in agriculture. He planted experimental crops in cotton, as well as a variation of purple maize, whose leaves could be used to make purple dye. He also imported Merino sheep and raised a prized flock.
When he wasn’t gardening or entertaining, John was quite the entrepreneur. A merchant by trade, he operated a ferry between Virginia and Georgetown; pushed for the construction of a toll road to Alexandria; invested in the Patowmack Canal Company (George Washington’s venture to make the Potomac River more navigable); and served as president of the Bank of Columbia in Georgetown.
He also speculated in land, which would prove to be his downfall. In 1833, the Bank of the United States foreclosed on Analostan Island, forcing John and his family (they had 10 children) to move to Clermont, a family farm four miles west of Alexandria.