The foundation stallion for the American White breed (previously known as the American Albino) was a stallion called Old King, who was foaled in 1906. King's ancestry was never recorded, and although it was generally though that he was of Morgan and Arabian blood, in photos he appears strongly Spanish in type with his sloping croup, broad chest, and heavily crested neck. According to those who had seen him, he was a true white with pink skin and brown eyes.
He was purchased in 1917 by Caleb Thompson to become the foundation for a new breed of white horses using mares of primarily Morgan blood. When bred to colored mares, half his progeny were white and 90% had his dark eyes. The Thompsons practiced inbreeding (mating close siblings) and it is said that many of his descendants produced 75% white foals. Old King died in 1924 from swamp fever.
Although King predated the registry, he became the foundation sire of the breed. His line was continued by his grandson Snow Chief II (Ambrose x Lucy II) who was foaled in 1932. The Thompsons had kept extensive records of their breeding stock and in 1937 the registry was established to record the progeny of Old King. Snow Chief was the first recorded entry. He died in 1947, having sired a total of 65 registered foals. One of his sons, Silver Chief, went on to help establish the American Cream draft breed. But probably Snow Chief's most famous son was White Wings (x Lady Ester) who was foaled in 1936. When the Thompsons sold Snow Chief II in 1943, White Wings took his place as senior stallion. White Wings sired a total of 106 foals, with all but three white.
White Wings' grandson, Thompson's Abraham, was retained by Ruth Thompson after the majority of the White Horse Ranch was dispersed in 1963. Thompson's Abraham lived to be 29 years of age. He was by the White Wings son Pegasus (x Snow White by Snow Chief II) and out of the mare Cotton (Zaydin x Lady Pal by Grant). Most of the remaining Old King American Whites trace back to White Wings, many through Abraham.
Although the stud books were opened to white horses of other bloodlines, and later an additional section added in 1970 for creams, the Old King horses are considered the original foundation bloodlines of the American White.