When Andrew Mellon donated his collection to form the
National Gallery of Art in the 1930s, he asked Congress to reserve land near to the Gallery for future expansion. By the 1960s, the Gallery needed that expansion. With funding from the Andrew Mellon Foundation and Mellon family members, the Gallery commissioned architect I. M. Pei to design a modernist wing to the east of the original building. Construction began for the new East Wing in 1971 and was completed in 1978.