Prairie School was a late 19th and early 20th century architectural style, most common to the Midwestern United States.

The works of the Prairie School architects are usually marked by horizontal lines, flat or hipped roofs with broad overhanging eaves, windows grouped in horizontal bands, integration with the landscape, solid construction, craftsmanship, and discipline in the use of ornament. Horizontal lines were thought to evoke and relate to the native prairie landscape.

The term Prairie School was not actually used by these architects to describe themselves (for instance, Marion Mahony used the phrase The Chicago Group); the term was coined by H. Allen Brooks, one of the first architectural historians to write extensively about these architects and their work.

The Prairie School developed in sympathy with the ideals and design aesthetics of the Arts and Crafts Movement begun in the late 19th century in England by John Ruskin, William Morris, and others. The Prairie School shared an embrace of handcrafting and craftsman guilds as a reaction against the new assembly line, mass production manufacturing techniques, which they felt created inferior products and dehumanized workers.

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 and completed 500 works. Wright believed in designing structures which were in harmony with humanity and its environment, a philosophy he called organic architecture. This philosophy was best exemplified by his design for 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.

His work includes original and innovative examples of many different building types, including offices, churches, schools, skyscrapers, hotels, and museums. Wright also designed many of the interior elements of his buildings, such as the furniture and stained glass. Wright authored 20 books and many articles and was a popular lecturer in the United States and in Europe. His colorful personal life often made headlines, most notably for the 1914 fire and murders at his Taliesin studio. Already well known during his lifetime, Wright was recognized in 1991 by the American Institute of Architects as "the greatest American architect of all time."