In darkness less than 50 yards away, a young man in a group of 20 or more college-age young people carousing on the beach in Sag Harbor Hills at about 10:15 p.m. on the night of July 4 yelled the racial epithet “N____r” at a group of black people as they were having a barbecue and playing Charades on the deck of a waterfront house on Ninevah Place.

Sunny Hostin, a legal correspondent for ABC, and a host of “The View,” and her guests couldn’t believe what they’d heard. She has been renting in the historically African-American community for 12 years and had always felt safe and secure there, she said.

“Everyone was so stunned. Everyone just jumped up. I thought I must have misheard,” said Ms. Hostin in a phone interview on Tuesday. “I know everyone on that beach but these voices were not familiar.”

One of her astonished guests called out, “Really?”

“Then they yelled it again,” Ms. Hostin said. “We were so stunned.”

“What?” one of her guests called.

“This is America!” came the reply, Ms. Hostin said. “We are patriots!”

“Yes, this is America,” answered one of her guests, after which the people on the beach began shooting off fireworks, Ms. Hostin said.

Ms. Hostin called the police. Officers “in one or two cars” arrived in minutes with emergency lights flashing, she said, but the crowd had scattered and police found no one on the beach.

The incident continued into the night, as the loud group came back calling the party “pussies” for calling the police. This time the police managed to stop two of the harassers and question them, the SagHarborExpress.com reported, in a story that stirred up the already anxious community. What used to be a mellow and sleepy town on the western coast on South Fork of Long Island was seeing a conversion in the post-Trump era. By mid-August, when I spent some time in the area, I realized that the incident may have been a symptom of the major transformation of the black community there, a minority enclave within an otherwise predominantly rich and white area.

For the last century and a half, the Hamptons has been the favorite of wealthy New Yorkers building their summer houses and socializing between them. But South Fork, Long Island, for the last 70 years also had an appeal for black Americans. Consisting of three small communities on the north side of Sag Harbor, all facing the bay and with access to the beach, the black summer resort on the west coast is modest, in comparison to Long Island’s east coast, from Southampton to Montauk, along which thousands of impeccable, manicured mansions and houses are scattered, complete with winding gardens, swimming pools, and tennis courts.

Azurest, Sag Harbor Hills and Ninevah are three communities with no rigid boundaries or fences. They feel more like a public square, an indication of life in a close-knit and closely-watched community. The author Colson Whitehead describes them as a significant part of his youth and named his fifth novel Sag Harbor. Whitehead, who spent most summers during his formative years in Sag Harbor, details the origin story of these communities, ascribing the existence of the black beaches in Sag Harbor to Maud Terry. Whitehead writes, “She was part of a group from Brooklyn and Queens who started coming out in the ‘30s and ‘40s, staying in the Eastville section, near the Hempstead House. Eastville was where the black and the Indian workers settled during Sag Harbor’s whaling boom, working the ships. One day our Maude, after walking through the dirt paths summer after summer to what would become Azurest Beach, decided to investigate who actually owned these woods.”

Mrs. Terry was a New York City school teacher who spent her summers in Eastville with her grandchildren. She eventually devised a plan to develop a more extensive black summer colony there. In the late 1940s, racial segregation still existed in the North and white landowners were reluctant to sell or rent to black buyers. Still, Mrs. Terry discovered the owners of the 20-acre tract of wooded land she fell in love with and, as the owners were eager to sell when Terry approached them with a plan to subdivide it and help sell the lots to her friends and colleagues in Brooklyn, the Gales agreed.

The beachfront lots went for $1,000 in 1948 and inland lots sold for $750. All this was before the construction of the Long Island Expressway when the trip from New York City or Brooklyn took a good four or five hours. Since Sag Harbor faces the bay and not the Atlantic coast, it was not as appealing or expensive as Bridgehampton or Southampton.

“Land and homeowners [in Azurest, Sag Harbor Hills, and Ninevah] read like a Who’s Who in Negro Society,” Ruby Holbrook wrote in “Story of Sag Harbor: Hick to Resort City.” From the early days, these developments were home to an impressive roster of black businessmen, judges, doctors, lawyers, artists, and diplomats.

Then, after ascending for 70 years, change came, Huffington Post reports:  

“As the generations shift and many of the older residents pass on or retire and migrate back down South, those in line to carry on the legacy — now in their 30s or early 40s — are often unable or unwilling to take up these homesteads. They have gone off to college, started careers and families elsewhere. Often they can’t handle the financial burden or would rather cash in on properties whose values have ballooned as much as ten times in some cases. Or they find no need for self-segregation, believing the whole world, even that of the white and the wealthy, has opened up for them in ways their forebears never could have imagined.”

The summers of Whitehead’s youth have long gone. The camaraderie of teenage boys and girls exploring the boundaries of the black enclave, manning expeditions to unfriendly, white-controlled territory, have evaporated. A friend who lives in Ninevah, though, told me that Whitehead now spends his summers in the Hamptons. As I roamed the area’s completely empty beaches in mid-August, finding a person I could talk to was not easy.  People are abandoning the black beach, and the three black communities in Sag Harbor are soon to be hamptonized with impersonal, fancy shops and restaurants for a posh American upper class.

Walking the side streets of Sag Harbor tells you how fast the properties are changing hands and being renovated from the bottom up. Sag Harbor, once the second most important port in the state of New York, is more a town than the Hampton villages on the other side of South Fork. The money now pours in, overwhelming Sag Harbor and its historic black enclaves. But Sag Harbor is still free from projects of extreme greed, as in the case of Ira Rennert, a billionaire who in the ‘90s built a $110 million mansion in Sagaponack that has somewhere between 21 and 29 bedrooms and between 18 and 39 bathrooms. There is not enough space to build such mansions, catering to the rich children of the New York Stock Exchange who’ve already saturated–flooded–the Atlantic coast.

“The racial makeup of the districts kept home prices down for decades with many white buyers choosing to live in other parts of the village,” explains the real estate report in the Washington Post from last year. Yet, that is changing as home prices in the Hamptons continue to rise, says Dianne McMillan Brannen, a broker with Douglas Elliman who has lived in Ninevah for more than 25 years. “Investors are being lured to these areas now and are looking for bargains,” she says. She estimates that about a dozen homes sold to investors last summer, up from four or five the previous year. “We welcome investment, but there is a real concern that these areas will lose the cultural identity that made them distinctive.”

“The communities of Sag Harbor Hills, Azurest, and Ninevah, SANS, are under the very same threat of extinction described by Dr. Kahrl in his book The Land Was Ours,” writes Victoria Sharp in her open letter to the editors of The East Hampton Star. “Starting in 2016, these neighborhoods have experienced the invasion of developers who hide their identity behind a series of L.L.C.’s. Most prominent among the developers is Robert Kapito, C.E.O. of BlackRock Investment, and his frontman, attorney Bruce Bronster. They reportedly own 20 properties in the three communities.” Sharp, who owns a small house on the edge of Ninevah, explains that the replacement of the modest homes of SANS with overscaled spec homes will lead to an increase in property taxes for everyone in the community. “The increase in property taxes will force elderly occupants, living on fixed incomes, to sell their properties. This is precisely the technique used by developers and described by Dr. Kahrl in his talk on the loss of African-American beachfront communities along the Eastern Seaboard,” Sharp said.

When put on the spot, Andrew W. Kahrl, points out: “The irony is that many of these places were deemed undesirable when African Americans first moved there. Some of these areas are gold mines today, but those luxury resorts in parts of coastal Georgia, South Carolina and around the Chesapeake were havens for African American life and culture.”

Black beach communities date back to the ‘30s in some coastal areas across America. They were a consequence of segregation when whites-only beaches dominated.

“For black people all during the first half of the 20th century, there were only three or four places to go like this all over the country,” said William Pickens III, a former corporate executive, and a local historian said. “There’s Oak Bluff in Martha’s Vineyard, Atlantic Beach in South Carolina, Highland Beach in Maryland,” he said. “But there has never been anything like the communities in Sag Harbor.”

“While I’m not happy to see the changes happening, I understand the how and why. Market forces are market forces,” Pickens said. “But what we are trying to do is encourage young prosperous black folks to take a good look at this place, to come in and compete for this property,” he said. “This is precious land, and we intend to keep as much of it as we can.”