When he started at Brooklyn Poly, John Trump was planning to become an architect and to go into business with his brother Fred. The two actually built one or two houses together, Mr. Walter said, but before long, they realized they had two very different philosophies.

''They laughed about it together later,'' their nephew said. ''John designed the house, and before it was finished, Fred wanted to sell it; you know, that's what you do when you're in real estate. But John was a scientist; he wanted to wait until it was totally done. After about a year, my uncle John switched to electrical engineering.''

As he grew older, Fred Trump began building single-family houses in the late 1920's -- most of them in Queens -- which were sold for $3,990 each. The concept of supermarkets was new back then, too, and when Mr. Trump built Trump Market in Woodhaven in the middle of the Depression and advertised, ''Serve Yourself and Save!'' it was an instant hit. About a year later, Mr. Trump sold the store for a profit to the King Kullen chain.

In World War II, Mr. Trump built barracks and garden apartments for the Navy in Chester, Pa., Newport News, and Norfolk, Va. When the fighting was over and apartments for returning servicemen and their families were in short supply, he branched out into middle-income housing; he built Shore Haven in Bensonhurst in 1949 and Beach Haven near Coney Island the next year for a total of 2,700 apartments. In 1963, he put up the 3,800-apartment Trump Village in Coney Island -- five years after his contemporary, Mr. LeFrak, began Lefrak City in Queens.

''He made a great contribution; he filled a very big hole in the market,'' Mr. LeFrak recalled. ''We took Queens; he did more in Brooklyn. He was a great builder who rallied to the cause like we did; he built housing for the returning veterans. I guess you could say we're the last of the old dinosaurs.''

In 1936, Mr. Trump married Mary McLeod, who had come to this country when she was 19 from Stornoway, Scotland. Miss McLeod had two sisters who lived in New York; shortly after she arrived, her sisters took her to a dance, where she met Fred Trump. They had five children. In addition to his wife and his sons Robert and Donald, he is survived by two daughters, Maryanne Trump Barry of New York City, who is a Federal judge, and Elizabeth Trump Grau of New York City. Another son, Fred Trump Jr., died in 1981. Both his brother John and his sister, Elizabeth Trump Walters, are dead.

Mr. and Mrs. Trump liked to assist young people who hungered for a career in real estate. Richard Levy, now a senior vice president at Tishman Real Estate, said that when he was in his early 20's, he remembers going to Mr. Trump's office, a reconverted dentist's office in the Beach Haven development near Coney Island. ''I felt like Custer,'' he said. ''There were all these huge wooden Indians all over the place.'' Mr. Levy looked at a wall ''covered with plaques from every organization and pictures with Presidents, and here's this giant of a man -- he was well over six feet -- and he just stuck out his hand and said 'Hi. My name is Fred.' ''