Born on Jul 18, 1876 to John Clark Thornton and Loretta Sloan Thornton. William A. Thornton passed away on Nov 4, 1933, at the age of 57 and was buried in Greenwood Cemetery in Grand Rapids, Michigan, United States. William A. Thornton was married to Jessie M. Johnston Thornton and had 1 children: John Leon Thornton.