In 1973, Ron and Loretta Martin and their three sons moved into the yellow-brick Colonial across the street from my childhood home, on Detroit’s west side. My father greeted them warmly, despite the fact that most of our neighbors saw them as blockbusters, part of a nefarious conspiracy by civil-rights groups to force integration and break up tight-knit white enclaves. The Martins were one of the first black families on our block. It took a lot of courage to be pioneers, those black families who crossed the city’s racial frontier. And it also took extra money. Black pioneers, as I discovered years later when I wrote a book about Detroit, were usually better off financially than the white people they moved next to. They had to be. Brokers regularly charged blacks a premium to buy or rent in what they hoped would be a safe, secure, integrated neighborhood.

Ron and Loretta were pioneers in another way. He was a police officer, she was a school teacher, and both were at the vanguard of a new generation of black Americans who vaulted into the middle class through public employment. Today, government employment, however fragile, is the mainstay of Detroit’s economy. At the beginning of 2013, the public sector directly provided more than forty thousand jobs in the city. Among Detroit’s top five employers are the city itself, the Detroit public schools, and the federal government. By contrast, the last two automakers with substantial operations in the city, Chrysler and General Motors, employ only about four thousand workers each.

It was not always this way. For most of the city’s history, there weren’t many Ron and Loretta Martins. The traditional avenue to a life of at least modest comfort for black Detroiters—at least after the Second World War, when the factory gates opened up—was the auto industry. The jobs were unionized, and they offered generous health and pension benefits. For the refugees from Jim Crow who’d come to the city, it was a big step up from the drudgery of tenant farming or cleaning houses.

But by the time the Martins moved in, those blue-collar jobs were disappearing. Beginning in the early nineteen-fifties, Detroit steadily hemorrhaged manufacturing jobs, losing them to outlying suburbs, small towns, the Sunbelt, and, over time, to Canada, Mexico, and overseas. Today, there is only one auto-assembly plant fully within the boundaries of Detroit.

Still, the children of auto workers began to benefit from the hard-won gains of the civil-rights movement: there were better schools than in the South, colleges that admitted blacks for the first time, and all sorts of jobs that, only a few years earlier, even in liberal cities like Detroit, had been for whites only. As the assembly lines halted, more and more blacks found new opportunities, like the Martins, as teachers and cops, or as social workers and firefighters, clerks and accountants, city attorneys and court reporters. Getting those jobs did not come without a struggle—civil-rights groups pressured city hall and filed lawsuits, and city agencies implemented controversial affirmative-action programs. But those efforts paid off. Public-sector jobs filled some of the gap left by manufacturing and provided a new generation of Detroiters with relatively high wages, health care, and pensions. By 1980, nationwide, over half of black professionals and managers worked in public-sector jobs.

Public employment, of course, did not come cheaply. The city’s budget began to groan under the weight of city workers’ paychecks and, even more so, under their health-insurance premiums and pensions. Those expenses rose at the same time that the city steadily lost population (which fell from its peak of 1.85 million in 1950 to just over seven hundred thousand today). That decline—and the downward spiral of auto-industry jobs—gutted the city’s tax base. And, unlike the cities that depended heavily on federal support for public works, housing, and jobs, in the long prosperous period from the forties to the early seventies, Detroit could not rely on Washington to help balance its budget. Federal urban spending fell sharply in the eighties, and Detroit simply did not have the political clout to win most of it back. And as the city’s older workers retired—and lived longer than ever before—the costs of pensions and health benefits ballooned.

Between 1990 and 2013, Detroit reduced its municipal workforce by nearly half to help make ends meet. But public employment remains one of Detroit’s few remaining lifelines. Government work keeps a lot of families afloat in a city where a sixth of the residents are unemployed, where sixty per cent of children live in poverty, and where some tens of thousands of homes stand empty.

Public employment brought the Ron and Loretta Martins of Detroit into the middle class; it provided them with the resources to own their own homes and send their children to college and pay their hospital bills and retire comfortably. Without public jobs, Detroit’s black middle class would have been a lot smaller, and the city’s decline would have been even steeper.

A few decades ago, Detroit barely survived the collapse of the auto industry. Bankruptcy poses just as pressing a crisis. The city will likely have no choice—short of the near-impossible prospect of a federal bailout—but to cut spending drastically, lay off workers, and axe pension and health benefits. But the cuts will exact a high price. The Detroit that emerges from bankruptcy will have a lot fewer Ron and Loretta Martins, and a lot less hope.

Thomas J. Sugrue is the David Boies Professor of History and Sociology at the University of Pennsylvania. His book on Detroit, “The Origins of the Urban Crisis,” won the Bancroft Prize in History.

Photograph by Bill Pugliano/Getty