The National Gallery of Art is a national art museum, located on the National Mall in Washington, D.C. Open to the public free of charge, the museum was established in 1937 for the people of the United States of America by a joint resolution of the United States Congress, with funds for construction and a substantial art collection donated by Andrew W. Mellon. Additionally, the core collection has major works of art donated by Paul Mellon, Ailsa Mellon Bruce, Lessing J. Rosenwald, Samuel Henry Kress, Rush Harrison Kress, Peter Arrell Brown 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 ever 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 (25,000 m2) Sculpture Garden. Temporary special exhibitions spanning the world and the history of art are presented frequently.

The Gallery's East Building was constructed in the 1970s on much of the remaining land left over from the original congressional joint resolution. It was funded by Mellon's children Paul Mellon and Ailsa Mellon Bruce. Designed by famed architect I.M. Pei, the contemporary structure was completed in 1978, and was opened on June 1 of that year by President Jimmy Carter. The new building was built to house the Museum's collection of modern paintings, drawings, sculptures, and prints, as well as study and research centers and offices. The design received a National Honor Award from the American Institute of Architects in 1981.

The final addition to the complex is the National Gallery of Art Sculpture Garden. Completed and opened to the public on May 23, 1999, the location provides an outdoor setting for exhibiting a number of pieces from the Museum's contemporary sculpture collection.

In contrast, the design of the East Building by architect I. M. Pei is rigorously geometrical, dividing the trapezoidal shape of the site into two triangles: one isosceles and the other a smaller right triangle. The space defined by the isosceles triangle came to house the museum's public functions. That outlined by the right triangle became the study center. The triangles in turn became the building's organized motif, echoed and repeated in every dimension. The building's most dramatic feature is its high atrium designed as an open interior court, it is enclosed by a sculptural space frame spanning 16,000 square feet (1,500 m2). The atrium is centered on the same axis that forms the circulation spine for the West Building and constructed in the same Tennessee marble.[5] Starting in 2005, the joints attaching the marble panels to the walls began to show signs of strain, creating a risk of panels falling off the building onto the public below. In 2008 officials decided that it would be necessary to remove and reinstall all the panels. The project is scheduled for completion in 2013.[6]

The East Building focuses on modern and contemporary art, with a collection including works by Pablo Picasso, Henri Matisse, Jackson Pollock, Andy Warhol, Roy Lichtenstein and Alexander Calder. The East Building also contains the main offices of the NGA and a large research facility, Center for Advanced Study in the Visual Arts (CASVA).

These photos were taken in March 3, 2003.