The Townsend House is one of the many elegant and often ostentatious mansions built along Massachusetts Avenue in the early decades of the 20th century. Completed in 1900 for Richard H. Townsend, a railway magnate, the mansion was designed by the well-known firm of Carrère and Hastings. Reflecting the taste of the period, the house incorporates Louis XV elements on a Beaux Arts-style facade. The Cosmos Club, a club whose membership includes distinguished men in the fields of science, literature and the arts, purchased the house in 1950.
The Townsend House, which incorporated the walls of the Hillyer House, was begun in 1898 and completed in 1900. The earlier house was built in 1873 by Curtis Justin Hillyer, an attorney engaged in mining speculation in California and Colorado. It is said that part of the Hillyer House was incorporated in the new mansion due to Mary Scott Townsend's superstitious fear of inhabiting a totally new home.
The house is named for Richard H. Townsend, who died in 1902, but his wife, coal and railroad heiress Mary Scott Townsend, continued to live there with her daughter, Mathilde, until 1931. The house was long at the center of Washington social activity, and it was said that Mrs. Townsend spent as much as $240,000 a year—the equivalent of more than $7 million today—for entertainment.
After Mrs. Townsend's death, Mathilde inherited the property, and it was during her ownership that the mansion became the temporary residence of Franklin Delano Roosevelt for a few weeks before he entered the White House. During World War II, in January 1942, the American Women's Volunteer service used the stables as a canteen. In 1943 the above group moved out, land the house was occupied by the Canadian Women's Army Corps Headquarters Detachment. In 1950, the house was purchased by the Cosmos Club, who maintain ownership today.