Discount store magnate Sam Moore Walton's estimated net worth of $ 4.5 billion makes him by far the wealthiest American, Forbes magazine reported yesterday in its annual ranking of the 400 Richest People in America.

But Forbes isn't sure who is the second richest person in the country. It's either John W. Kluge of Charlottesville, the one-time wholesale grocery salesman who created the giant Metromedia Corp., or H. Ross Perot of Dallas, who recently sold his Electronic Data Processing Corp. to General Motors. Each is worth about $ 2.5 billion, according to Forbes, which keeps score yearly on how the truly wealthy are doing.

The richest people in Washington, Forbes said, are members of the secretive Mars candy family: John F. Mars, 51, of Arlington, and his brother, Forrest E. Mars Jr., 55, of McLean. Their father, Forrest E. Mars Sr. now lives in Las Vegas. Each of the Mars family members is worth $ 1.3 billion, the magazine said. The Mars brothers are two of three billionaires in Washington, Maryland and Virgina; Kluge is the third.

This year 56 people made the Forbes 400 Richest list for the first time, including Eastern Shore chicken king Frank Perdue, estimated to be worth $ 200 million; fashion designer and merchandiser Ralph Lauren, worth $ 300 million; and TV personality Dick Clark, who has rocked and rolled his way from "American Bandstand" to a $ 180 million fortune.

That's the minimum required to make the 400 Richest list this year, because the rich keep getting richer. Last year a net worth of $ 150 million would make the cut.

Several millionaires haven't been able to make money fast enough to keep up and have been dropped off the list this year. Among the no-shows are singing cowboy Gene Autry; Generoso Pope Jr., owner of The National Enquirer; and Trans World Airlines Chairman Carl T. Icahn, whose $ 175 million net worth left him a "near-miss" in this year's ranking.

There are 26 billionaires in the fifth annual Forbes' listing, up from 14 last year. The new billionaires include Barbara Cox Anthony and Anne Cox Chambers, whose Cox Enterprises media group owns the TV show "Lifestyles of the Rich and Famous."

Walton, who made his fortune building Wal-Mart discount stores in small-town America ("There was a lot more business in those towns than people ever thought") saw his wealth jump about 60 percent from $ 2.8 billion in the past year.

Kluge, 72, took control of Metropolitan Broadcasting in 1959. He took the company private in 1984 in a bold $ 1.2 billion buyout and has been liquidating ever since. Perot, 56, founded his own company in 1962 and sold it to GM in 1984 for $ 1.2 billion. He is currently a GM director.

Next on the list are David Packard, Los Altos, Calif., cofounder of Hewlett-Packard ($ 2 billion); investor Warren Buffett of Omaha, a longtime investor in The Washington Post Co. and Geico Corp ($ 1.4 billion); and Leslie Wexner, founder of The Limited Inc. ($ 1.4 billion).

While the total of 26 billionaires is a record, Forbes magazine said there would have been more if it weren't for the 120-point tumble in the Dow Jones average in mid-September. The drop came just before the magazine priced all publicly held stocks to determine the net worth of the 400.

The average age of the richest rich is 62.3 years. Seventy-seven are women. And there is still a chance to marry great wealth: The list includes 39 unmarried women and 53 unmarried men.

Inheritance remains the most reliable way to get really rich: 168 of those on the Forbes list inherited substantial parts of their fortunes. There are 174 self-made millionaires, who acquired their wealth without financial help from ancestors.

Motown Records' Berry Gordy, worth $ 180 million, made the list this year, the second black. John Harold Johnson, the Chicago publisher of Ebony magazine, was the first black included in the Forbes 400. He has an estimated net worth of $ 185 million.

Malcolm Forbes is rich enough to make the list, but once again he declined to say how much he's worth. Other publications have estimated his worth from $ 200 million to more than $ 1 billion.

Several financiers made the list for the first time, including Mike Milken, Drexel Burnham Lambert & Co.'s "junk bond" king ($ 500 million); former Treasury Secretary William Simon ($ 200 million); Irvin (The Liquidator) Jacobs ($ 180 million); and Saul Steinberg, whose public offering of his Reliance Group Inc. brought him to $ 650 million net worth.

More than 5 percent of the list represents du Pont money; another 5 percent is held by Mellons and Rockefellers.

Last on the list are Jerome Kohlberg Jr., Henry Kravis and George L. Roberts of leveraged buyout fame, worth $ 180 million each, and Armand Hammer, chairman of Occidental Petroleum Corp. ("I'm worth plenty"), whose net worth is estimated at just above $ 180 million.

Big losers are Dallas' Hunt family. Margaret Hill Hunt was the only family member to remain in the billionaire class; Nelson Bunker Hunt, who dropped from the billionaire class a while back, saw his wealth sag by 55 percent to $ 400 million. Brothers William Herbert and Lamar are worth $ 350 million and $ 250 million, respectively.

Although none of the top five is from New York City, that city has the largest number of super-rich, with 90, followed by Los Angeles with 26 and Dallas-Fort Forth with 25.