Cass Gilbert, leading American Beaux-Arts architect, was born in Zanesville, Ohio, on November 24, 1859, the son of Gen. Samuel Augustus and Elizabeth Fulton (Wheeler) Gilbert. He attended public schools in Zanesville and St. Paul, Minnesota, and worked as a carpenter's helper and draftsman for Abraham Radcliff in Saint Paul in 1876. In 1878 he entered Massachusetts Institute of Technology, where he studied architecture with William R. Ware. Early in 1880 Gilbert made a study trip to England, France, and Italy and on his return joined the prominent New York firm of McKim, Mead, and White. In 1882 he returned to St. Paul and established his own practice. He formed a partnership with James Knox Taylor in 1884 that lasted until 1892. During their joint practice Gilbert and Taylor built numerous residences, churches, and municipal buildings, as well as the Minnesota State Capitol. Gilbert's work on the capitol brought him national recognition, and in the early 1890s he received a commission for the multistoried Brazer Building in Boston (1896). He moved to New York around 1899 to work on the Broadway-Chambers Building and settled there permanently. During the next three decades he was one of the most renowned architects in America. His work included such well-known New York buildings as the United States Customs House (1901–07), the Union Club (1902), and the Woolworth Building (1912), which at the time of its completion was the world's tallest building.
Between 1910 and the early 1920s Gilbert drew up a number of development plans for the University of Texas campus. None of the plans was implemented, but some aspects of Gilbert's proposals were adopted by Paul P. Cret in the 1930s. Gilbert also designed two buildings for the Austin campus, Sutton Hall (1918) and Battle Hall (1911), the latter widely recognized by architectural historians as one of the finest works of architecture in the state. Designed in a Spanish-Mediterranean revival style, the two buildings became the stylistic basis for the later expansion of the university in the 1920s and 1930s and helped popularize the style throughout the state.
Gilbert was one of the founders of the Architectural League of New York and served as its president in 1913–14. He was also a member of the National Institute of Arts and Letters, the American Academy of Arts and Letters, and the American Institute of Architects and an honorary member of the Royal Institute of British Architects. He married Julia T. Finch of Milwaukee, Wisconsin, on November 29, 1887; the couple had several children. Gilbert died in Brockenhurst, England, on May 17, 1934.