Claude A.P. Turner was born in Lincoln, Rhode Island on July 4, 1869. He graduated in 1890 from the school of engineering at Lehigh University, (Bethlehem, Pennsylvania). He worked for numerous companies, including the New York & New England Railroad, Edgmore Bridge Co. (Philadelphia), Columbus (Ohio) Bridge Co., Pittsburgh Bridge Co., and Pottsville Iron & Steel Co. (Pennsylvania), before coming to Minneapolis in 1897. Turner was employed as an engineer with the Gillette Herzog Company and American Bridge Company until 1901, when he formed his own firm. In 1908, he received a patent for the flat-slab support system (also called the "mushroom cap" column system) in reinforced concrete, which he used in many later buildings and bridges. He went on to be granted more than 30 more patents for reinforcement and reinforced concrete.

Turner's structures included the Duluth Ferry Bridge (1906); Johnson-Bovey Building (1905-1906) and Wisconsin Central Freight Station (1907), Minneapolis; Lindeke-Warner Building (1908-1909), Hamm Brewing Co. stockhouse (1907), and West Publishing Co. (1910), St. Paul; Soo Line Railroad bridge, New Richmond, WI (1910-1911); Hoffman Building (1906), Milwaukee; courthouses in Green Bay, WI, Fairmont, MN, and Vinton, IA, and the South Dakota State Capitol, Pierre. Turner died in Columbus, Ohio on January 10, 1955.