Born in Latvia in 1881, Harry Beck found his way to Roxbury. In 1940, when a man from the census knocked on their door, Beck told him he worked as a cobbler, 60 hours a week in his own shop. His son worked as a chemist, earning $1,500 a year.

The Becks were part of a strong Eastern European presence in Roxbury, one of a generation of upwardly mobile immigrant families that helped transform Boston from a blue-collar city to a professional one, reshaping life in almost every neighborhood.

That process, and the families that were part of it, are captured in the recently released 1940 census, the first to provide detailed information about employment and ­education. The richly detailed report captures a singular moment in the city’s history.

An informal Globe survey of representative city streets, following the census takers’ footsteps from home to home to glimpse the lives within, conveys the texture of life in Boston at the time and foreshadows the sweeping changes to come.

“The world you’re seeing is being eclipsed,” said ­Robert Allison, chairman of the History Department at Suffolk University.

In 1940, the census shows, the city was dominated by machinists and mechanics, laborers and craftsmen. Of the 270,000 workers in Boston, just 27,500 worked as professionals. By comparison, there were more than 73,000 clerical and sales workers (including more than 5,000 traveling salesmen and some 700 “hucksters and peddlers”), and about 34,000 craftsmen, foremen, and kindred workers.

Workers of the time made their living by making things, the records show. On Crawford Street in Roxbury, in a working-class neighborhood of black and immigrant families, Ida Herman, a 59-year-old from Lithuania, stitched dresses, earning $663 for the year. On Salem Street in the North End, Virginio Ralli, a 53-year-old from Italy, set boilers to support his wife and three children. On East Second Street in South Boston, Ignatius Keymont, a 61-year-old from Lithuania, worked as a motor parts machin­ist, earning $1,560.

The records show that jobs of any kind were hard to come by. More than 13 percent of Boston’s labor force was looking for work, and another 6 percent was on public emergency work projects, typically through New Deal programs such as the Civilian Conservation Corps and the Works Progress Administration.

Family by family, the records lay out the toll of unemployment, echoing contemporary economic woes.

On Crawford Street, Joseph Bernstein lived with his parents, Lithuanian immigrants in their 60s. A 27-year-old college graduate, Bernstein had worked in a laboratory as a medical assistant, but had been out of work for more than a year.

On Cross Street in the North End, Milano Santosuosso, a 44-year-old from Italy, was looking for work as a tinsmith, while his daughter, a 17-year-old “new worker,” was looking for her first job. His brother-in-law and a lodger, a plumber and roofer, respectively, had been unemployed for nearly two years.

Nearby on Hanover Street, Italian immigrant Umberto Volpe, 43, worked as a stonemason for the Works Progress Administration, earning $800 a year. His stepson, 20, had been looking for work for a year.

On K Street in South Boston, James Connolly, a husband and father of six, had been a stock clerk but was looking for work. His oldest daughter, 21-year-old Mary, was a stenographer at a gas company.

Unsealed earlier this year, the records bring to life ­Boston’s neighborhoods and the contours of families’ lives. Block by block, home by home, the responses present history on a personal scale: where people came from, where they worked, how many children they had, even how much they paid in rent.

“It’s a snapshot of who people are, and how they lived,” ­Allison said.

Marge Ellis, a researcher who has traced her family back to the 1700s, said the census ­records show the depth and complexity of Boston’s neighborhoods where people from different backgrounds and ethnicities lived side by side, a ­dynamic mix of old and new.

“It’s not just an enumeration of names and streets,” she said. “It’s the joy of this country.”

Given the economic constraints, multiple generations often lived together far more ­often than today. Around the corner from 163 Crawford St., on Hollander Street, Willis and Harriet Rose, a black couple in their 60s, lived with their two adult daughters and two grandchildren, 7 and 4.

Willis Rose worked odd jobs, while his daughter Emily, 25, worked as a servant, earning $200 a year. Her older sister, Geraldine, was a waitress who had been unemployed for six months.

On Crawford Street, another black couple, Harry and ­Jeanette Wright, raised their children, 17 and 12. Harry Wright, 40, who dropped out of high school after one year, worked as a butler. Jeanette Wright, 38, who had completed college, worked as a servant. Jeanette Wright’s parents, from North Carolina, were also living with them.

At 422 Hanover St. was the Passacantilli family, who lived above their restaurant, the well-known Blue Front. Three years after the census, Victor Passacantilli was born into a teeming North End that felt like a giant family, in a world apart.

“It was like living on an ­island,” Passacantilli recently recalled. He scarcely left the North End until seventh grade, when he started school at ­Boston Latin, which proved a “culture shock beyond belief.” But when the train dropped him home at day’s end, he felt understood again.

“It was where everyone talked like me, dressed like me, ate like me,” he said. “It was where we seemed to belong.”

Filled with large, first- or second-generation Italian families, the neighborhood was a bustling place where people looked out for each other and word traveled fast. For the children who romped through the streets looking for fun and prone to mischief, that kinship sometimes came at a cost.

“No matter where I was, if I stole an apple off a fruit stand, my mom would find out about it,” he said. “Everyone knew every­one.”

Over time, the neighborhood changed, and Passacantilli moved out of the city. But on Wednesdays, when Passacantilli joins a group of older men who grew up in the North End, it lives as before.

“We just sit around and reminisce,” he said.