In 1923 , Louis Blaustein and his son , Jacob Blaustein , sold half a share of their American Oil Company to Pan American in return for a guaranteed oil supply . In 1923 Louis Blaustein and his son Jacob Blaustein sold a half interest in their American Oil Company to Pan American in exchange for a guaranteed supply of oil . In 1923 , Jacob Blaustein and his son , Louis Blaustein , sold half a share of their American Oil Company to Pan American in exchange for a guaranteed oil supply .