The National Gallery of Art, and its attached Sculpture Garden, is a national art museum in Washington, D.C., United States, located on the National Mall, between 3rd and 9th Streets, at Constitution Avenue NW. Open to the public and free of charge, the museum was privately established in 1937 for the American people by a joint resolution of the United States Congress. Andrew W. Mellon donated a substantial art collection and funds for construction. The core collection includes major works of art donated by Paul Mellon, Ailsa Mellon Bruce, Lessing J. Rosenwald, Samuel Henry Kress, Rush Harrison Kress, Peter Arrell Browne Widener, Joseph E. Widener, and Chester Dale. The Gallery's collection of paintings, drawings, prints, photographs, sculpture, medals, and decorative arts traces the development of Western art from the Middle Ages to the present, including the only painting by Leonardo da Vinci in the Americas and the largest mobile created by Alexander Calder. The Gallery's campus includes the original neoclassical West Building designed by John Russell Pope, which is linked underground to the modern East Building, designed by I. M. Pei, and the 6.1-acre (25...