Complex sentence: In July 1942, Princequillo made his American racing debut and after a few races was purchased by Boone Hall Stable, owned by Prince Dimitri Djordjadze of Georgia and his American-born wife, Audrey Emery.
Split into simpler sentences: In July 1942, Princequillo made his American racing debut. After a few races, he was purchased by Boone Hall Stable, owned by Prince Dimitri Djordjadze of Georgia and his American-born wife, Audrey Emery.