What is more, these jobs pay people more. According to the Bureau of Labor Statistics, manufacturing workers typically earn just over $26 an hour. By contrast, medical orderlies and nurse’s assistants (a growing field) earn half as much. And fast food, a mainstay for Americans with a high school diploma or less, has a median hourly wage of $9.11.

For Mr. Branch, this is not abstract economics.

“This changed my life,” he said, standing next to one of the machines he operates, which can cost up to $300,000 each. “I went from minimum wage at Popeyes to making almost 70K a year. They’re proud of me in my old neighborhood. They say I made it out.”

With the rise of Donald J. Trump, much of the economic debate during the presidential campaign has centered on the anger and economics of the white working class in the Rust Belt and elsewhere. That is partly because blue-collar whites were especially hard hit by factory closures in the last decade, largely as a result of competition from China and the savage recession eight years ago.

But it was the black working class that was devastated first, by a decades-long decline of manufacturing employment.

As the sociologist William Julius Wilson has written in his classic studies, “The Truly Disadvantaged” and “When Work Disappears,” the exodus of factories from high-cost, union-dominated cities to cheaper, less union-friendly locales in the South and West in the 1960s and 1970s played a major role in the breakdown of urban cores.

“The trends among non-college-educated, white Americans today look like a lot like the trends among black Americans in the 1970s that so worried policy makers and social scientists,” said David Autor, a professor of economics at M.I.T., who researches the connections among trade, labor and employment. “You see it in the falling labor force participation, the decline of traditional family structure, crime and poverty. It’s all there.”

While some cities, including Boston, Chicago, New York and Pittsburgh, have managed to rebound in recent years, Baltimore remains mired in a cycle of economic and social dysfunction. Unemployment among young black men tops 35 percent, compared with 31 percent nationally, and among large cities, Baltimore experienced the largest percentage increase in murders in the nation over the last two years.