Frank Lloyd Wright (born Frank Lincoln Wright, June 8, 1867 – April 9, 1959) was a first generation Welsh-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 the Fallingwater house (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 in Broadacre City, his unique vision for urban planning in the United States. His creative period spanned more than 70 years. In addition to his houses, Wright designed original and innovative offices, churches, schools, skyscrapers, hotels, museums and other structures. He often designed interior elements for these buildings as well, including furniture and stained glass. Wright wrote 20 books and many articles and was a popular lecturer in the United States and in Europe. Wright was recognized in 1991 by the American Institute of Architects as "the greatest American architect of all time".His colorful personal life often made headlines, notably for leaving his first wife, Catherine Lee "Kitty" Tobin for Mamah Borthwick Cheney, the murders at his Taliesin estate in 1914, his tempestuous marriage and divorce with second wife Miriam Noel, and his relationship with Olga (Olgivanna) Lazovich Hinzenburg, whom he would marry in 1928.