Since its opening in 1931, the collection has grown to 12,000 paintings, sculptures, prints, drawings, photographs, from 2,000 artists. It provides the most complete overview of 20th-century American art in the world. The collection focuses on key artists. From 1900-50: Edward Hopper, Alexander Calder, Reginald Marsh, and Stuart Davis. The building's inverted pyramid construction allows 30,000 square feet of exhibition space in a building on 97 feet tall.