William Zeckendorf was born in 1905 in Paris, Illinois, the son of a hardware store manager, and moved to New York City at age three. He dropped out of New York University, learned real estate at his uncle’s firm and joined the brokerage Webb and Knapp, which he bought outright in 1949. In 1946 he used option contracts to lock up 17 acres of slaughterhouses and tenements along Manhattan’s East River, from roughly 42nd to 48th Street, planning a dream city to rival Rockefeller Center. He sold the land for $8.5 million to architect Wallace Harrison and Nelson Rockefeller, and John D. Rockefeller Jr. donated it as the site of the United Nations headquarters.

Zeckendorf went on to own the Chrysler Building, the Hotel Astor and the Commodore, bought Frank Lloyd Wright’s Robie House, and became an early patron of I.M. Pei with projects such as Denver’s Mile High Center. In Montreal he brought together Royal Bank of Canada chief James Muir and Mayor Jean Drapeau to build Place Ville Marie. In 1958 he agreed to buy 176 acres of 20th Century Fox’s backlot for $53 million to build Century City, though he lacked the money, and paid a $1,000-a-day penalty while construction stalled. A 1960 partnership with Alcoa financed the project. Webb and Knapp went bankrupt in 1965, and Zeckendorf died in September 1976 after a stroke, still in bankruptcy proceedings.

• To revive press belief in Century City, publicists staged a groundbreaking where Mary Pickford smashed champagne on a tin shack before a bulldozer flattened it.
• Freedomland USA, built with Disneyland developer C.V. Wood on Bronx marshland, closed in 1964 after five years.
• Zeckendorf later said the park was a placeholder to secure roads, sewers and rezoning, and the land became Co-op City.
• Co-op City became the largest cooperative housing development in the world.
• In his final years Zeckendorf worked for his son William Jr.’s firm while his wages were garnished to pay creditors.