Robert E. Simon Jr. at the 10th anniversary of Reston in 1974. (DOUG CHEVALIER/The Washington Post)

Robert E. Simon Jr., a real estate entrepreneur described as a visionary when he carved the planned community of Reston out of the Northern Virginia countryside in the 1960s, only to be forced out when tensions arose over financing and slow sales, died Sept. 21 at his home in Reston. He was 101.

The Reston Historic Trust announced the death. No cause was provided.

Although Mr. Simon remained indelibly linked to Reston — the Fairfax County town was named for his initials, R.E.S. — he spent much of his career in the New York City area. The scion of a prominent real estate family, he had in his 20s succeeded his late father as head of the corporation that operated Carnegie Hall.

Reston was a departure from most of Mr. Simon’s ventures, which included shopping centers and other commercial projects. But after selling Carnegie Hall to New York City in 1960 for ­$5 mil- lion, he said he needed to invest his profits quickly before being hit with a massive capital gains tax.

He was intrigued when a real estate broker told him of a parcel of land that had just become available: 6,750 acres of wooded fox-hunting territory 18 miles west of Washington.

The broker told Mr. Simon that three huge pluses were nearby: a superhighway called the Capital Beltway; a world-class airport, Dulles International; and a high-speed access road that linked the Beltway and the airport.

Mr. Simon soon learned that none of those amenities existed yet. Undeterred, he saw the chance to create a community that was the antithesis of uninspired and, in many cases, racially and economically segregated postwar suburbs.

“With a parcel this size, the only conceivable single use was a bedroom community, and that, to me, was a repulsive idea,” said Mr. Simon, who favored Birkenstock sandals and sported a goatee.

Mr. Simon said he envisioned a town where fathers would not live the way he did early in his married life — as a harried commuter who didn’t get home from downtown until 8 p.m. and had neither the energy nor time to spend with his family.

He said he wanted to create a self-contained community: a place where people could go to the office, do their shopping, have dinner, get haircuts for their children, visit an art gallery and attend the ballet — all without leaving the town borders. Among the amenities was Lake Anne, named for his second wife and inspired by the Italian coastal village of Portofino. Over the years, the town hosted regattas on the man-made lake.

For $800,000 in cash and a $12 million mortgage, Reston was born. Zoning for the community was approved by the Fairfax County Board of Supervisors in 1962. Construction and sales began in 1963, and Mr. Simon became a national celebrity who attracted flattering profiles in major newspapers and magazines.

Reston, as initially planned by Mr. Simon, would be built around village clusters, with homes and shops next to one another. It would not revolve around car travel. It would not destroy natural beauty unnecessarily. It would emphasize hiking, biking and outdoor living.

The community would blend single-family houses, apartments and townhouses, and would be aggressively marketed to people of all races and income levels.

“The banks tried to have us change our system and to go all white,” Mr. Simon told an interviewer decades later, adding that he eventually persuaded financial institutions to support the mixed-race development.

This was a daring proposition at a time when Virginia law still prohibited interracial marriage. Not until 1967 did the U.S. Supreme Court strike down the state law as a violation of the Constitution’s equal protection clause.

Ada Louise Huxtable, a noted architecture critic, wrote in the New York Times in 1967 that Reston “ran counter to every standard practice and procedure of conventional real estate development. Standard practice means the sleazy subdivision and the asphalted shopping center, the familiar fast-buck operation, composed of short-term, quick profit, in-and-out financing and instant obsolescence.”

Michael Southworth, an authority on urban design who teaches at the University of California at Berkeley, said in an e-mail interview that Reston was “part of a movement to create better planned towns and cities that integrated all components of urban life, including shopping, recreation, culture, education, industry, transportation and housing of various types.”

“It was a response,” Southworth wrote, “to sprawling, auto-depen-dent, segregated suburban tract developments that lacked many of the ingredients for making a good community.”

From its earliest phases, Mr. Simon’s utopian vision ran up against some ugly financial and social realities. Sales remained far behind projections during its first four years. Townhouses were considered too expensive. According to a Time magazine article of the era, apartment rents were pegged too low for Mr. Simon to cover his mortgage payments.

Real estate agents steered buyers away from Reston because they said it was “communist,” Mr. Simon later told Reason magazine. “It was the black thing, of course — the integration. And the townhouses. There were no townhouses in the boonies until Reston.”

Mr. Simon began borrowing millions of dollars from John Hancock Mutual Life Insurance Co. and from Gulf Reston, a subsidiary of Gulf Oil that had promised the infusion of cash for exclusive rights to provide gasoline, heating oil and other fuel to the community.

In 1967, Gulf Reston took over daily management of the development and injected the project with $15 million. Bob Ryan, Gulf Reston’s on-site manager, called Mr. Simon a “visionary with no business sense.” The project’s board pressured Mr. Simon to resign as chairman. When he refused, he was fired.

Mr. Simon was given 24 hours to leave his company-provided house. Infuriated, Mr. Simon’s wife threw the furniture slipcovers into the garbage and, as a vivid rebuke, left behind a copy of Truman Capote’s “In Cold Blood,” according to the book “Reston: The First Twenty Years.”

Although he remained publicly upbeat, Mr. Simon said he privately feared that Gulf would transform the town into a traditional subdivision. The company only slightly modified Mr. Simon’s original concept, veering away from villages and toward more widespread traditional, single-family suburban homes. Sales improved steadily.

The U.S. Geological Survey moved its headquarters to the town in the early 1970s and private companies followed, including General Electric, Sperry and AT&T. By 2010, Reston had become home to more than 62,000 residents and 55,000 jobs.

Mr. Simon told the Associated Press he took away the lesson that “if the initial developer doesn’t have access to an infinite amount of money, I mean billions of dollars, he is going to be vulnerable. . . . I’m project-oriented and not sufficiently finance-oriented.”

Robert Edward Simon Jr. was born in New York City on April 10, 1914. His father, who had developed a pioneering planned community in New Jersey called Radburn, died in 1935, the year Robert Jr. graduated from Harvard University. The younger Simon took over the family company.

Mr. Simon’s first wife, the former Helen Adam, died in 1959 after 20 years of marriage. His later marriages, to Anne Wertheim Langman and Dorothy Monet, ended in divorce.

Survivors include his wife of 11 years, Cheryl Terio-Simon of Reston; a daughter from his first marriage, Margo Prescott-Morris of Florida; several stepchildren; and many grandchildren and great-grandchildren. A son from his first marriage, Paul Simon, died in 1991.

After his work in Reston, Mr. Simon returned to the New York area and conceived and managed smaller-scale real estate projects. He retired at 79, then settled in an 1,800-square-foot apartment overlooking Lake Anne.

He became active in local affairs — writing letters to local newspapers, serving on the board of the Reston Association and holding court most mornings at a coffee shop near his home. A lifelike bronze statue of Simon was placed on a bench beside Lake Anne in 2004, on his 90th birthday.

In recent years, Simon watched with mixed emotions as Metro’s Silver Line arrived in Reston, with its first stop nowhere near any residential or retail centers. But he was thrilled to be consulted by developers rehabilitating the Lake Anne shopping center and nearby apartment complex, saying their plan followed his original vision of creating a “walkable community.”

Last year, Reston turned 50 the same year that Simon turned 100. The town celebrated him, he was still a regular around the Lake Anne Village Center and he still had plenty of opinions about the need for a performing-arts theater, better bus service and a bigger library. “Community,” Simon said. “That word is the whole discussion. . . . I think having facilities readily available for people of all kinds, from little kids to the elderly — that’s the most important thing of all.”

Bob Levey is a former Washington Post columnist. Tom Jackman contributed to this report.