David Nasaw is up to a bit of historical revisionism in "Children of the City," and he makes a most persuasive job of it. His focus is the first two decades of the 20th century, a period commonly believed to have been unduly unpleasant for the inhabitants of American cities and all the more so for their children, much of whose time was spent in dirty and dangerous streets. Nasaw's conclusion is quite to the contrary: His research has convinced him that while life for city children in these years was far from easy, on the whole it was educational, productive and enjoyable.

"Children of the City" concentrates on "children born to working-class parents who owned little or no property, had received little or no formal education, and worked for wages or piece rates at skilled or unskilled jobs" -- precisely those children whose experiences we would expect to conform to the stereotyped view of the period. These were children whose parents were first- or second-generation immigrants, who lived in cramped, malodorous quarters, who had little acquaintance with green spaces or fresh air, who were expected to work to help support their families, who had only the streets in which to play.

But those streets seem to have been considerably less threatening places than we imagine. Street life, Nasaw writes, was "an active, organized community with its own structures of authority, law and order." Contrary to popular belief, "the streets were not jungles and the children were not savages." Left largely to their own resources by parents who were busy scraping out their meager livings, the children created a world in the streets that was remarkably safe, considering the potential threats it contained, and that offered them an instructive introduction to the world they would soon enough enter as adults:

"The street was their playground, but it was also a marketplace, meeting ground, social club, place of assignation, political forum, sports arena, parade grounds, open-air tavern, coffeehouse and thoroughfare. The life on the street was the life of the city. While the children played, the policemen walked their beat, prostitutes solicited 'johns,' peddlers shouted their wares, delivery wagons squeezed down the block to neighborhood shops, and men and women clustered in small groups on the corners, in front of the shops, at the threshold of the saloons, and on their front steps."

The children were as much a part of this clamorous scene as anyone or anything else, and they made their way in it with impressive self-confidence. Their play was unstructured, much to the dismay of settlement workers and other do-gooders, but they fitted it into the life of the street in ways that caused minimal danger to them and relatively little disruption for others. As for their work, it developed into a productive part of the urban economy; the combination of the slow decline of the sweatshops and the appearance of the child-labor laws moved them out of abusive full-time labor and into part-time jobs for which they were ideally suited.

These jobs permitted them to work for part of that daily period between the close of school and nightfall. Their work included street trading in various forms, running as messengers and, above all, hawking afternoon newspapers. The newsboy, or "newsie," was a small but noisy and energetic presence in every city, and an extremely important person to the newspaper that he sold. This was before the development of more sophisticated newspaper distribution; the newsboy was a cheap, remarkably effective sales agent, and newspapers needed him so badly that he had genuine independence in the marketplace. So pivotal was his role, in fact, that in 1899 a strike by New York newsboys forced both Hearst and Pulitzer to capitulate to them -- a David-besting-Goliath phenomenon that may be unique in American history.

By the 1920s the era of the street children was over; they had been "pushed to the side by the automobile, which cut off their play and work space, by tougher and better-enforced child-labor laws, and by adults who moved into the trades they had once monopolized." But for those who had lived in the street, the lessons they learned lasted through life: "In meeting its dangers and clearing a play and then a work space for themselves, they developed confidence in their strength of purpose and their powers to make their own way." They became a generation of cocky, purposeful men and women who believed in the Horatio Alger vision, in the idea that America was "the land of opportunity and beacon of freedom for the poor and oppressed." As Nasaw amply documents, they played an important role in American history, and in "Children of the City" he has given them their due.