J.P. Morgan, Andrew Carnegie, John D. Rockefeller: These are names people think of when they talk about the Gilded Age. But Marm Mandlebaum? Not so much.

And yet, in her fascinating new book, “The Talented Mrs. Mandelbaum,” Margalit Fox makes a convincing case that Fredericka “Marm” Mandelbaum made a significant impact in that heady era, as a pioneering entrepreneur — of stolen goods. Fox tells the improbable story of Mandelbaum, who arrived at the port of New York in steerage in 1850 and died as a notorious millionaire and a fugitive of the law nearly 50 years later.

Mandelbaum and her husband, Wolf, began their American lives working as they had in Germany, as peddlers, living in a string of tenements in Kleindeutschland (Little Germany) on the Lower East Side of Manhattan, where streets were not always paved, sanitation was iffy and diseases ravaged families. By that time, the city’s population had swelled to 900,000. Robber barons sat atop the social pyramid. Materialism was unabashed. As an American middle class grew, so did regulatory organizations emerge. Now doctors had to become licensed. Lawyers now had to attend and graduate from real law schools and be recognized by the bar association. Police departments began codifying and enforcing codes of behavior for their new forces for the first time.

Mrs. Mandelbaum recognized that peddling could only keep her afloat, and that from her position very few opportunities would be possible: Being a laundress, a maid, or a prostitute wouldn’t do. Making real money was her goal. “It was here, at the intersection of thrift, stuff, class, and desire, that Fredericka Mandelbaum found her calling,” Fox writes. She cleverly skirted rules as she ascended the socioeconomic ladder.

We’ve all heard of the “underworld,” of course, but Fox explains its opposite, the “upperworld.” Her book explores how Mrs. Mandelbaum served a link between those two realms. Marm (sometimes known as “Mother Mandelbaum”) had no interest in being a big shot in the seedy corners of the underworld. She took her place at the head of the table in brightly lit salons where being a Jewish mother served her well.

By paying off the right people, mentoring protégées, being generous with her network of criminals — footing expenses, paying bail and keeping defense lawyers on permanent retainers — Mandelbaum brought a level of professionalism to her illegal activities. She hosted company picnics and elegant parties. “There was pleasure, solidarity and security in being a thief in the Mandelbaum syndicate,” Fox writes. For a while, her best thieves drew a regular salary.

By 1860, Mandelbaum had become a renowned figure in New York. For one thing, her physical stature made her impossible to ignore. Towering about six feet tall, Mandelbaum resembled “the product of a congenial liaison between a dumpling and a mountain,” Fox writes. For another, she was generous to her neighbors, philanthropic to her community, and a devoted synagogue member. Consequently, she was respected and adored, like the nice lady who lived next door, and not like a crime boss. Yet she was both. She was a thief who befriended the mayor, many judges and cops. She would teach her shoplifters how to dress appropriately to blend in with the crowd — whether they were spending an hour at Tiffany & Co. or impersonating a janitor at the Manhattan Savings Institution. She financed stakeouts and commissioned the manufacture of the finest safecracking equipment imaginable.

As a child, this reviewer once stole a tiny pencil from the stationery store and felt so sick over her crime that she confessed immediately to her mother, who walked her back to apologize in shame and tears. So the brazenness of a crime godmother such as Mrs. Mandelbaum floored me. Fox, a longtime obituary writer for the New York Times and author of three previous books, including “The Confidence Men,” excels at telling a story that is rich in historical detail; one sees the beginning of the modern era in America’s most important city.

Mandelbaum was sophisticated in her management skills. She “took great care not to have stolen goods dispatched directly to her shop.” Instead, she had them kept at one of the many properties she rented in and around the city. Within her building on the corner of Clinton and Rivington streets, she had a simple dry-goods store — the fence’s front — as well as an “effacement chamber,” where workers freed gemstones from their settings, erased hallmarks from jewelry and silver, removed manufacturers’ identifications from bolts of silk and so on. There was a trick chimney, a trapdoor, a hidden parlor for Mrs. Mandelbaum to be able to spy on transactions, and a thieves’ dormitory. Oh, and yes, the family apartment where somehow four children were raised.

Mandelbaum, who “dressed soberly but expensively in vast gowns of black, brown or dark blue silk, topped by a sealskin cape,” threw extravagant parties. Both the uptown swells and the elite crooks would be invited. New Yorkers yearned to be asked to them. (In 1991, the New York gossip columnist Cindy Adams threw a birthday party for her husband, Borscht Belt comedian Joey Adams. The guest list included Leona Helmsley, Bess Myerson and Imelda Marcos — all public figures who were tainted by scandal or crime. Joey Adams said famously, “If you’re indicted, you’re invited.” It was perhaps a less original idea than we thought.) By the mid-1870s, Marm Mandelbaum was the elusive mastermind on many reformers’ arraignment wish lists. But she was “rarely arrested” and even when she was, her cases were rarely brought to trial.

But that changed in 1884, when a man posing as a wannabe fence learning at the master’s feet turned out to be a plant working for the Pinkerton National Detective Agency. Allan Pinkerton, the eponymous founder, had famously protected President Abraham Lincoln during the Civil War. Unlike the sundry police departments, Pinkerton agents “had full power of arrest.” On July 22, Marm Mandelbaum was arrested by his son Robert Pinkerton, at the behest of zealous District Attorney Peter B. Olney.

By now a widow who had recruited her two sons to her business, Mandelbaum stood trial in one of those “trial of the century” court cases Americans enjoy every year or so. In her case, it really was. Her lawyers were just as colorful as their client. The firm of Howe & Hummel, “the unofficial bar of the New York underworld,” were known for “bribing, swindling, slandering” and worse. Spectators flooded the courthouse. After weeks of courtroom maneuvering, Mandelbaum’s lawyers requested a transfer of the case to a higher court and when, several months later, that trial was to finally start, Mandelbaum had fled to Canada. The tale of her life as a brazen and shrewd crime boss and then her escape to and life as a fugitive is enthrallingly cinematic, and Fox, who will be writing the screenplay for the film version of this book, captures every detail.

When Fredericka Mandelbaum was buried, “it was reported afterward, some mourners deftly picked the pockets of others. Whether they did so in tribute to their fallen leader or simply from occupational reflex is unrecorded.” A fitting end to a fascinating life story. I cannot wait for the movie.

Lisa Birnbach is a writer and a humorist.

The Talented Mrs. Mandelbaum

The Rise and Fall of an Organized-Crime Boss

By Margalit Fox

Random House. 336 pp. $32