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Welcome to Anderson House (Lydia DePillis)

Anderson House, at 2118 Massachusetts Avenue, doesn’t particularly stand out as a mansion in a row of mansions. It might be the only one controlled by an exclusive hereditary organization tracing back to the Revolutionary War, though.

Continuing with my interest in imposing buildings controlled by secretive groups, I stopped into Anderson House one recent Saturday, when it’s open to the public between 1:00 and 4:00 p.m. The collection inside is as worth visiting as any Smithsonian—just much more idiosyncratic.

American diplomat Larz Anderson III built the house from 1902 until 1905, with the then-astonishing sum of $750,000, to be his winter residence and entertainment venue (his main residence, in Brookline, Mass., was ten times the size). He and his wife Isabel filled it with artifacts from their travels; Isabel’s favorite was a collection of mineral trees and a dragon figurine. A Buddha oversees the pool in the back garden.

The opulence is hard to wrap your brain around. The Andersons bought one car per year, for a total of 36; the sun-filled back hall has murals of their favorite driving routes through pre-war Washington. There are ceilings made of 23-karat gold, floors inlaid with 50 kinds of marble, and walls covered with ancient Flemish tapestries. You can almost hear the clink of fine china and the bewildering array of silverware used in their formal dinners, oddly offset by a modest kitchen with charming white cabinets and rubber floors.

The beautiful ballroom.

2118 Massachusetts’ days as am individual’s trophy residence are long over, though. When Larz Anderson died in 1937, Isabel donated the house to the Society of the Cincinnati, of which her husband had been a devoted member. Isabel herself, of course, never could have joined: The Society is reserved to the male descendants of Revolutionary War officers. According to our tour guide, about 5,000 potential members have been identified, but only about 3,100 have actually joined up. Benefits of membership include free stays in the Anderson’s house’s antique-filled rooms (though donations are expected) and a splendid meeting every three years at various locations around the country. At these triennial summits, the Society elects its new Presidents General, and their photos—invariably labeled with three-part names, like Jonathan Tufts Woods and Ross Gamble Perry—adorn the walls.

For all its venerability, it’s unclear what the Society actually accomplishes. In the exhibit on the group’s history, Presidents General are lauded for their efforts to chronicle the Society’s meetings, strengthen the members’ fraternal bonds, and identify new lines to bring into the fold. The group’s stated mission is to “perpetuate the memory of the achievement of independence”—benign enough, I suppose, for a group intentionally limited to blue-blood white men.

Don’t let the creepy monarchalism of the place keep you from visiting, though. There’s a fantastic library in the basement, and a full schedule of free public concerts and lectures on various Revolutionary-era subjects. Just make sure to think hard about the achievement of independence while you’re there.

Ghostly illumination.

Isabel Anderson's favorite, mineral trees. (Lydia DePillis)

The Andersons' driving route.