What is origin of the term million dollar family?

Think it derives from the similar terms "rich man's family" or "choix du roi"

One son--to inherit and rule the estate...no brothers are needed to work the fields or run the business (because you're rich) so best deal is not to have second and third sons who will not receive a birthright and will skulk around, envious, making trouble

One daughter--to marry a powerful ally's son and spread your power and influence