The APHA was started in Gainesville Texas to register stock horses that were not eleigilble for registration in the AQHA.
The paint and qh both came from spainish stock mustangs and TBs.
The origins of both breeds are the same. That is why for years any QH with excessive white was accepted for full registration into the APHA even without one registered APHA parent. TBs with enough white can also be registered. Until the early 80's horses were still inspected and registered if they met the stock horse requirements. Shalom