SAN FRANCISCO — Standing at the stoop of her childhood home — a slim but stately Victorian shaded by an evergreen pear tree — Lynette Mackey pulled up a photo of a family gathering from nearly 50 years ago. The men were all in suits, the women in skirts. Ms. Mackey, a teenager in red bell bottoms, stretched her arms wide and had a beaming smile.

Soon after that time, in the 1960s and 1970s, Ms. Mackey watched the slow erasure of Black culture from the Fillmore District, once celebrated as “the Harlem of the West.” The jazz clubs that drew the likes of Billie Holiday and Duke Ellington disappeared, and so, too, did the soul food restaurants.

By the mid-1970s, many of her friends were gone as well, pushed out by city officials who seized homes in the name of what they called “urban renewal.” Then, finally, her family lost the house they had purchased in the 1940s after migrating from Texas. In many cases, the old Victorian homes were torn down and replaced with housing projects, but the city kept Ms. Mackey’s home standing, and it has since been renovated into government-subsidized apartments.

Her grandfather suffered a heart attack while fighting to save their home. “He died saying, ‘I’m not going to sell this house,’” she said.

Today, against this backdrop of loss and displacement, San Francisco is weighing reparations that would compensate Black residents for policies that drove them away and hindered their economic opportunities. Cities across the country are studying similar restitution, but none have been as ambitious as San Francisco, whose 15-member task force has issued 111 recommendations in a preliminary report to city leaders.

To close the racial wealth gap, long a central argument for reparations, the task force has declared a moonshot: a one-time, $5 million payment to anyone eligible. By comparison, California’s state reparations task force has recommended a sliding scale that tops out at around $1.2 million for older Black residents.

The cash figure has grabbed headlines, but it is widely seen as unrealistic in a city that has growing budget problems and a lack of political consensus on the issue. The $5 million payments could top $100 billion — many times the $14 billion annual budget in San Francisco — and London Breed, the city’s mayor, has not committed to cash reparations.

Ms. Mackey, 63, who stayed in the city, is working toward a more likely path of securing incentives for other long-ago Black residents and their descendants to return to San Francisco. One idea is for the city to provide them with housing subsidies, access to affordable housing and stipends for moving expenses.

San Francisco’s Black population has shrunk from 13 percent in 1970 to about 5 percent today, driven first by cycles of redevelopment and then by the gentrifying forces of tech employers. Black residents have been pushed into outlying Bay Area suburbs with cheaper housing and long commutes, if not other cities and states.

When thousands of Black migrants arrived in the 1940s to work in the shipyards, housing practices confined them to either the Fillmore District or Bayview-Hunters Point, a blustery southeast corner of San Francisco. The center of Black cultural life in the Fillmore no longer exists, and today, the biggest share of San Francisco’s Black population lives in Bayview-Hunters Point. But even that neighborhood is about 30 percent Black now compared with more than 75 percent in 1980.

“There’s not too many people who were born here that are still here,” said Oscar James, 77, who has lived in Bayview-Hunters Point his whole life and bought a house in 1978. “A lot of people have either passed away or moved away.”

When the city seized homes in the Fillmore, it issued certificates to families that would allow them to receive public housing. Since then, the documents “have not been tracked and have rarely been honored,” the reparations task force wrote. The story of Black displacement was the subject of the 2019 movie, “The Last Black Man in San Francisco,” in which the main character laments the loss of his family’s Victorian.

Ms. Mackey, who now rents a subsidized apartment in the Fillmore, recently has been working for a city program that uses a private investigator to track down people who lost their homes to redevelopment in the 1960s and 1970s and inform them of their rights to receive public housing benefits.

“Everyone knows the impact of slavery,” said Majeid Crawford, whose nonprofit, New Community Leadership Foundation, is working with the city to locate former residents. “But we also had our own apartheid that took place in San Francisco through urban renewal.”

As a child, Aliciea Walker had to move out of San Francisco when her family’s three-story Victorian in the Fillmore was lost to redevelopment. She finished her schooling in nearby Half Moon Bay, and eventually settled in Sacramento.

Now 63, Ms. Walker said she hasn’t paid close attention to the reparations debate but hopes San Francisco will make it easier for former Black residents to return.

“My bags are ready to go back to San Francisco, because that’s my children’s childhood and that’s my childhood,” said Ms. Walker, who for part of her adulthood lived in a rental in San Francisco, where she raised young children.

The reparations task force cited several factors, beyond the redevelopment sweep, that have left Black residents behind, from a statewide ban on affirmative action to discriminatory barriers that have resulted in less access to health care. So how does a city compensate them for what was lost?

Task force members believed the $5 million figure would settle “the decades of harms,” said Eric McDonnell, a management consultant and lifelong San Francisco resident who chairs the panel.

“Our mission was not a feasibility study,” he said. “It was, assess the harm, assign the value.”

What’s feasible is the big question, however. Every member of the board of supervisors, which will consider legislation later this year after receiving the task force’s final report, has expressed support for some form of reparations, although not all believe that has to be in cash payments.

Mayor Breed, who would qualify for reparations as a Black resident who grew up in the city, has been noncommittal, saying she would evaluate the task force’s final report. Jeff Cretan, her spokesman, said the mayor is focused on her Dream Keeper Initiative, a grant program established in 2020 that he said “is putting money in the African American community right now.” Last month, Ms. Breed said she wasn’t planning to support a proposal to spend $50 million on a city reparations office.

The Rev. Amos Brown, who has led Third Baptist Church in the Fillmore since 1976, has seen similar discussions play out over the decades. Sitting in a conference room at his church, Mr. Brown pointed to the rich history of his neighborhood — Maya Angelou working in a record shop, the Black Panthers giving out books and food — and to the many commissions on the decline of Black San Francisco he has been part of over the years.

Despite past promises going unfulfilled, he said, he’s “very, very cautiously optimistic” that the city will enact some form of reparations, even if he fears the $5 million idea could give false hope to Black residents.

“Of all these billionaires in San Francisco, you could establish a reparations fund,” he said.

Reparations for Black Americans have been debated since the end of the Civil War. In recent years, the idea gained traction as influential voices argued for reparations, and momentum grew during the racial justice protests in 2020 following the police murder of George Floyd.

The movement has extended to a number of local governments. Modest programs offering restitution to Black residents have been established in Evanston, Ill., Providence, R.I. and Asheville, N.C.

In San Francisco, the task force focused in particular on the redevelopment in the 1960s and 1970s when the authorities declared entire blocks to be “blighted” and used eminent domain to purchase businesses and homes. The panel called it the “most significant example of how the City and County of San Francisco as an institution played a role in undermining Black wealth and actively displacing the city’s Black population.”

Ms. Mackey now talks to people who have left San Francisco, some decades ago, tracking down housing certificate holders in Hawaii, Alaska and elsewhere. Often, she said, they are still angry over the displacement. Many of the original certificate holders have died, and their descendants often know nothing of their family’s story of loss in San Francisco.

She dreams of a Black renewal in her city. Reparations in the form of housing aid may persuade some to return, but she knows how challenging that dream is today.

“Almost everyone says the same thing,” she said. “That they cannot afford to live in San Francisco.”