Museum in Washington, D.C., part of the Smithsonian Institution .
It was founded in 1937 when Andrew W. Mellon donated his collection of European paintings to the U.S. He also donated funds to construct the gallery's Neoclassical building, opened in 1941. Now known as the West Building, it is connected by plaza and underground concourse to the East Building, designed by I.M. Pei (completed 1978). The museum houses an extensive collection of U.S. and European paintings, sculpture, decorative arts, and graphic arts from the 12th to 21st centuries; especially well represented are works by Italian Renaissance, 17th-century Dutch, and 18th-and 19th-century French artists.