The District of Columbia War Memorial commemorates the citizens of the District of Columbia who served in World War I. The memorial stands in West Potomac Park slightly off of Independence Avenue in a grove of trees. Authorized by an act of Congress on June 7, 1924, funds to construct the memorial were provided by the contributions of both organizations and individual citizens of the District. Construction of the memorial began in the spring of 1931, and the memorial was dedicated by President Herbert Hoover on November 11, 1931 (Armistice Day). It was the first war memorial to be erected in West Potomac Park, and remains the only local District memorial on the National Mall.

From Wikipedia

http://en.wikipedia.org/wiki/District_of_columbia_war_memorial