Rich Americans

Bill Gates, seen here addressing the 63rd session of the United Nations General Assembly at UN headquarters, Sept. 25, 2008, is the richest American with with $59 billion, according to Forbes magazine.

The Forbes 400: The richest people in America

Warren Buffett: $39 Billion

Billionaire investor Warren Buffett, speaking at a news conference about a documentary movie called "I.O.U.S.A.," in Omaha, Neb., Aug. 21, 2008, is the second richest American. Forbes puts his net worth at $39 billion.

Mark Zuckerberg: $17.5 Billion

Facebook founder and CEO Mark Zuckerberg, seen here in Deauville, France, May 27, 2011, is the youngest billionaire on the list at age 27.

Eduardo Saverin: $2 Billion

Eduardo Saverin, the co-founder of Facebook, seen here on April 28, 2011, in New York, is worth $2 billion. In January 2011, it was reported Saverin was the lead investor in, Qwiki, a Silicon Valley start-up.

Mark Cuban: $2.3 Billion

Mark Cuban, owner of the Dallas Mavericks, is seen here at the Mavericks victory celebration, June 16, 2011, in Dallas, Texas. Cuban is also involved with HDNet and Magnolia Pictures. He appeared as himself in a storyline on several episodes of HBO's series "Entourage."

David Koch: $25 Billion

David Koch, seen here with his wife Julia at Lincoln Center, Nov. 25, 2008, in New York, is worth $25 billion, reports Forbes. His brother Charles is worth the same amount. The Koch brothers were the subject of a 2010 New Yorker piece called "Covert Operations: The billionaire brothers who are waging a war against Obama."

Sergey Brin, Larry Page: $17.5 billion

Google co-founders Sergey Brin, left, and Larry Page, seen here at the International Book Fair in Frankfurt, Germany, Oct. 7, 2004, have an estimated net worth of $17.5 billion, says Forbes.

Ty Warner: $2.4 Billion

Ty Warner, creator of Beanie Babies toys, is seen here at the American International Toy Fair, Feb. 16, 2003, in New York. He's one of five people ranked at No. 166.

Anne Cox Chambers

At 91, Anne Cox Chambers is the oldest woman on the list. She seen here on Nov. 13, 2009, in Paris. Chambers is a media proprietor.

George Soros: $22 Billion

George Soros, seen here on Jan. 27, 2011, in Davos, Switzerland, is worth $22 billion, reports Forbes.

Larry Ellison: $28 Billion

Oracle CEO Larry Ellison, with an estimated net worth of $33 billion, is the third richest American and among the top 10 in the world, ahead of Mukesh Ambani of India ($29 billion) and Lakshmi Mittal ($28.7 billion). Mittal is a citizen of India but lives in the UK.

Christy Walton & Family: $22.5 Billion

Christy Walton, widow of the late John Walton, seen here, and her family is the fourth richest in the U.S. and the 11th richest in the world. She is the daughter-in-law of the late Sam Walton, Walmart's founder. Edging her out on the global list were Bernard Arnault of France ($27.5 billion), Eike Batista of Brazil ($27 billion), Amancio Ortega of Spain ($25 billion), Karl Albrecht of Germany ($23.5 billion), and Ingvar Kamprad & family of Sweden ($23 billion).

Jim Walton: $20.7 Billion

Jim Walton, youngest son of the Walmart founder, is worth $20.7 billion, according to Forbes, putting him on the list as as the fifth richest American and 15th richest in the world. Listed ahead of him are Stefan Persson of Sweden ($22.4 bilion) and Li Ka-shing of Hong Kong ($21 billion).

Alice Walton: $ 20.6 Billion

Alice Walton, daughter of Walmart founder Sam Walton, is worth $20.6 billion, according to Forbes. That makes her the sixth richest in America and 16th richest in the world.

David Rockefeller: $2.5 Billion

At 96, David Rockefeller is the oldest billionaire on Forbes' list of Americans. He's seen here at MoMA's 41st Annual Party in the Garden at The Museum of Modern Art, on May 26, 2009, in New York.

Sumner Redstone: $4.1 Billion

Viacom chairman Sumner Redstone is worth $4.1 billion and is 80th on the Forbes list. He's seen here on May 24, 2010, in New York.

S. Robson Walton: $19.8 Billion

Walmart Chairman S. Robson Walton, is the seventh richest American with a net worth of $19.8 billion. On the global list, he is number 18, separated from his siblings by Liliane Bettencourt of France with a net worth of $20 billion.

Michael Bloomberg: $18 Billion

New York Mayor Michael Bloomberg, seen here with companion Diana Taylor at a state dinner at the White House, Nov. 24, 2009, is the country's eighth richest person. His estimated net worth of $18 billion makes him 23rd richest in the world. Ahead of him are Prince Alwaleed Bin Talal Alsaud of Saudi Arabia ($19.4 billion), David Thomson and family of Canada ($19 billion), Michael Otto and family of Germany ($18.7 billion), and Lee Shau Kee of Hong Kong ($18.5 billion).

Steve Ballmer: $14.5 Billion

Microsoft CEO Steve Ballmer, photographed making a presentation at the Mobile World congress in Barcelona, Spain, Feb. 15, 2010, is the 10th richest American and the 33rd richest in the world. Forbes estimates his net worth at $14.5 billion.

Jeff Bezos: $19.1 Billion

Amazon founder and CEO Jeff Bezos, seen here at Consumer Reports, May 11, 2011 in Yonkers, New York, is worth $19.1 billion, says Forbes.