D.C. Code § 47-1043
Certain property in the District of Columbia described as lots no. 36 and 37 in square no. 2,517, as recorded in the Office of the Surveyor of the District of Columbia in liber 64, at folio 69, together with the improvements thereon and the furnishings therein, being premises no. 2340 S Street Northwest, known as the Woodrow Wilson House, owned by the National Trust for Historic Preservation in the United States, a corporation chartered by Act of Congress approved October 26, 1949, be exempt from all taxation, so long as the same is used in carrying on the purposes and activities of the National Trust for Historic Preservation in the United States, and is not used for commercial purposes, subject to the provisions of §§ 47-1005, 47-1007, and 47-1009. Use of the premises by agencies of the United States of America or by any organization exempt from federal income taxation for museum purposes or conference accommodations shall not affect the exemption from taxation provided for herein.
D.C. Code § 47-1043