Society of the Cincinnati Headquarters (Anderson House)

From www.culturaltourismdc.org:

This Italianate palace known as Anderson House was built between 1902 and 1905 for career diplomat Larz Anderson III, and his wife, writer Isabel Weld Perkins. Although the limestone walls present a closed feeling from the street, once inside, you'll experience a grand openness from the large windows that face the south garden. The main floor is embellished with portraits and murals of family heroes, and you can almost see the ghosts in long gowns waltzing around the magnificent two-story ballroom. Anderson House is now the headquarters of the Society of Cincinnati, a benevolent organization established by George Washington for his officers and their direct male descendants. The Society maintains a genealogical library and research center.