The US may not have any rich royals, but it does have rich families with net worths in the billions. These billionaire clans have accumulated their fortunes in vastly different ways, from publishing and cosmetics to retail and hotels. See the top 25 richest families in the US, ranked by net worth, starting at $10 billion. America may not be home to any rich royal families, but that doesn't mean some families haven't created their own sort of empire. In fact, the United States has quite a few billionaire clans who accumulated their fortunes in vastly different ways.