Bartlesville, Oklahoma (1956). The building is unusual that it is supported by its central core of four elevator shafts; the rest of the building is cantilevered to this core, like the branches of a tree. Wright originally planned the structure for an apartment building in New York City. That project was cancelled because of the Great Depression, and he adapted the design for an oil pipeline and equipment company in Oklahoma. He wrote that in New York City his building would have been lost in a forest of tall buildings, but that in Oklahoma it stood alone. The design is asymmetrical; each side is different. In 1943 he was commissioned by the art collector Solomon R. Guggenheim to design a museum for his collection of modern art. His design was entirely original; a bowl-shaped building with a spiral ramp inside that led museum visitors on an upward tour of the art of the 20th century. Work began in 1946 but it was not completed until 1959, the year that he died. Walter Gropius and Marcel Breuer Walter Gropius, the founder of the Bauhaus, moved to England in 1934 and spent three years there before being invited to the United States by Walter Hudnut of the Harvard Graduate School of Design; Gropius became the head of the architecture faculty. Marcel Breuer, who had worked with him at the Bauhaus, joined him and opened an office in Cambridge. The fame of Gropius and Breuer attracted many students, who themselves became famous architects, including Ieoh Ming Pei and Philip Johnson. They did not receive an important commission until 1941, when they designed housing for workers in Kensington, Pennsylvania, near Pittsburgh., In 1945 Gropius and Breuer associated with a group of younger architects under the name TAC (The Architects Collaborative). Their notable works included the building of the Harvard Graduate School of Design, the U.S. Embassy in Athens (1956–57), and the headquarters of Pan American Airways in New York (1958–63). Ludwig Mies van der Rohe Ludwig Mies van der Rohe described his architecture with the famous saying, "Less is more". As the director of the school of architecture of what is now called the Illinois Institute of Technology from 1939 to 1956, Mies (as he was commonly known) made Chicago the leading city for American modernism in the postwar years. He constructed new buildings for the Institute in modernist style, two high-rise apartment buildings