stylistic:tone
Prairie Style houses (1900–1914)

By 1901, Wright had completed about 50 projects, including many houses in Oak Park. As his son John Lloyd Wright wrote:

William Eugene Drummond, Francis Barry Byrne, Walter Burley Griffin, Albert Chase McArthur, Marion Mahony, Isabel Roberts, and George Willis were the draftsmen. Five men, two women. They wore flowing ties, and smocks suitable to the realm. The men wore their hair like Papa, all except Albert, he didn't have enough hair. They worshiped Papa! Papa liked them! I know that each one of them was then making valuable contributions to the pioneering of the modern American architecture for which my father gets the full glory, headaches, and recognition today!

Between 1900 and 1901, Frank Lloyd Wright completed four houses, which have since been identified as the onset of the " Prairie Style ". Two, the Hickox and Bradley Houses, were the last transitional step between Wright's early designs and the Prairie creations. Meanwhile, the Thomas House and Willits House received recognition as the first mature examples of the new style. At the same time, Wright gave his new ideas for the American house widespread awareness through two publications in the Ladies' Home Journal. The articles were in response to an invitation from the president of Curtis Publishing Company, Edward Bok, as part of a project to improve modern house design. "A Home in a Prairie Town" and "A Small House with Lots of Room in it" appeared respectively in the February and July 1901 issues of the journal. Although neither of the affordable house plans was ever constructed, Wright received increased requests for similar designs in following years. Wright came to Buffalo and designed homes for three of the company's executives: the Darwin D. Martin House (1904), the William R. Heath House 1905), and the Walter V. Davidson House (1908). Other Wright houses considered to be masterpieces of the Prairie Style are the Frederick Robie House in Chicago and the Avery and Queene Coonley House in Riverside, Illinois. The Robie House, with its extended cantilevered roof lines supported by a 110-foot-long (34 m) channel of steel, is the most dramatic. Its living and dining areas form virtually one uninterrupted space. With this and other buildings, included in the publication of the Wasmuth Portfolio (1910), Wright's work became known to European architects and had a profound influence on them after World War I.

Wright's residential designs of this era were known as "prairie houses" because the designs complemented the land around Chicago. Prairie Style houses often have a combination of these features: one or two stories with one-story projections, an open floor plan, low-pitched roofs with broad, overhanging eaves, strong horizontal lines, ribbons of windows (often casements), a prominent central chimney, built-in stylized cabinetry, and a wide use of natural materials – especially stone and wood.

By 1909, Wright had begun to reject the upper-middle-class Prairie Style single-family house model, shifting his focus to a more democratic architecture. Wright went to Europe in 1909 with a portfolio of his work and presented it to Berlin publisher Ernst Wasmuth. Studies and Executed Buildings of Frank Lloyd Wright, published in 1911, was the first major exposure of Wright's work in Europe. The work contained more than 100 lithographs of Wright's designs and is commonly known as the Wasmuth Portfolio.