Frank Lloyd Wright (born Frank Lincoln Wright, June 8, 1867 – April 9, 1959) was an American architect, interior designer, writer, and educator, who designed more than 1,000 structures, 532 of which were completed. Wright believed in designing structures that were in harmony with humanity and its environment, a philosophy he called organic architecture. This philosophy was best exemplified by Fallingwater (1935), which has been called "the best all-time work of American architecture". Wright was a leader of the Prairie School movement of architecture and developed the concept of the Usonian home, his unique vision for urban planning in the United States. Frank Lloyd Wright was an architect for about 70 years.