Microsoft co-founder Bill Gates tops the list with a net worth of $54 billion, followed by famed financier and investor Warren Buffett, worth $45 billion.
Other notable people on the list include the heirs to the Wal-Mart retail fortune and New York City Mayor Michael Bloomberg, all in the top 10.
Meanwhile, Facebook co-founder Mark Zuckerberg jumped to number 35 on the list, more than doubling his net worth to almost $7 billion.
Forbes says members of the finance, investment and real estate industries dominate the list, taking up a total of 140 spots..
The U.S. state of California has the most members on the list of wealthiest Americans, followed by New York, Texas and Florida.
While many of those on the Forbes list increased their personal fortunes, the two wealthiest Americans have been encouraging billionaires to give their wealth away.
Buffett and Gates say they have already persuaded 40 of the richest families and individuals in the United States to give at least half of their fortunes to charity as part of the "Giving Pledge" campaign.
Earlier this year, Forbes named Mexican billionaire Carlos Slim the world's richest person. At the time, the telecommunications mogul boasted a fortune worth $53.5 billion, placing him slightly ahead of Gates (whose fortune was an estimated $53 billion when the list was released).
adapted from VOA News
