In Arizona cattle country, early settlers naturally competed to see whose horse was fastest or who had the best working ranch horse, beginning the race and show tradition at Sonoita. The Sonoita Quarter Horse Show began at the Santa Cruz County Fair and Rodeo Association fairgrounds in 1939, and many exhibitors isolated by distance saw it as a good place to compete with horses from the region, including the versatile Lightning Bar, sire of Doc Bar, one of the most influential cutting horse sires in history. By 1949, early issues of The Quarter Horse Journal brought results of the Sonoita show to a national audience. Unofficial race meets are recorded as far back as 1915, with race results first appearing in the AQHA Chart Books in 1954. Except for a short span during World War II, Sonoita has provided an early-season opportunity for an owner to see how a particular horse will run. Many great horses competed there, including world champions Ed Grimley, Mars Blackman, and Sign it Super; Mark T Bars, the all-time leading winner with a record 64 career wins out of 115 official starts; Pies Royal Request, co-holder of the all-time record 14 consecutive wins and the former world record holder at 330 yards; and Fast Copy, dam of stakes winners including champion Heza Fast Man. Many notable horsemen and women contributed to Sonoita's distinctive legacy in the arena and on the track. American Quarter Horses compete in races around the world and are in demand for showing, ranch work, rodeo, recreational riding, and many other activities, and AQHA is the world's largest equine breed registry, with its international headquarters in Amarillo, Texas.