Barnes was the grandson of one of Kansas City's earliest architects, Asa Beebe Cross. Cross designed many homes on Quality Hill as well as the original Jackson County Courthouse and Union Depot. Union Depot, located in the West Bottoms, was the predecessor to Kansas City Union Station.[1]
Barnes was married to Clara F. Knotter on August 29, 1931. They had two daughters, Geraldine "Gerry" Claire (Conrath) and Catherine Anne (Scott). The family had an interest in historical preservation. Alfred Barnes was a member of the Native Sons of Kansas City and preserved many of the blueprints and other artifacts of Hoit, Price and Barnes. After his death, Clara donated these and other family artifacts to the State Historical Society of Missouri which created the collections of "Asa Beebe Cross (1826-1894) Papers (K0082)" and "Alfred Edward Barnes (1892-1960) Architectural Records (K0004)." The former includes a school paper titled "Biography of A.B. Cross by Gerry Claire Barnes, great granddaughter."[citation needed]