American Quarter Horse Association History in 4 parts. Quarter Horse Journal, beginning April 1953 (? Biog. of William Barry Warren, 1st president of Assoc. Quarter Horse Journal v.12 #5 Feb., 1960 p.9, 124-125, 128 1961 convention held in Denver Jan. 17-18; schedule of activities. The Quarter Horse Journal v.13 Jan., 1961 pp.41, 69-70 1973 president is William R. (Bill) Thompson. Cattleman My 1973 p.147 Registers 2,000,000th horse. Quarter Horse Journal v.3fi #1 0 19831!0,p.288-290