Who the riches man in USA?

As of my last update in September 2018, the richest person in the United States was Jeff Bezos, the founder and CEO of Amazon. His net worth was estimated to be around $153 billion. However, please note that this information could be outdated as wealth can fluctuate over time. It's always a good idea to check a reliable and up-to-date source for the most current information on the richest individuals.