You thought the ’70s were bad? Tell that to a New Yorker from the 19th century, when prostitution, along with many other vices, was just a normal part of life in the city. In this excerpt from his new book, “Law & Disorder: The Chaotic Birth of the NYPD” (St. Martin’s), out Tuesday, historian BRUCE CHADWICK reveals the call-girl scene in mid-1800s New York, in shocking detail . . .

The bloody slaying of hooker Helen Jewett in the spring of 1836 did not end prostitution in New York City; it energized it. Five years after Helen was butchered with an ax, anywhere from 3,000 to 10,000 prostitutes worked in a community of whorehouses, on street corners and even in the balconies of exquisite theaters, where they thought nothing of propositioning men in front of their wives.

Numerous prostitutes saved room money by servicing clients in their business offices. Many staked out territories such as particular saloons or docks. One enterprising 15-year-old girl became the prize hooker for men who worked on a particular coal barge.

Prostitution was very profitable. Women who worked in high-end brothels in Midtown New York west of Broadway, or in expensive “parlor houses” such as the one on Thomas Street where Jewett died, could clear, after fees to madams and room and board, close to $50 a week, or some $300,000 a year in today’s money. Even dirty street-urchin girls could earn 50 cents for quickie masturbations, or more than $100 a trick in today’s money. A girl who relieved three men a day — not uncommon — could earn the equivalent of $100,000 a year.

The work was not easy for hookers, though, in whatever era they worked. One study done in the early years of the 20th century showed that a woman in a slum whorehouse coupled with 19 men a day for a week and on one day slept with 28. Two other hookers in that house had sex with between 120 and 150 men a week, and one day one of them had sex with 49 men. Some young girls would have sex with 15 to 20 men in a three-hour period. Many of the girls were 12 and 13 and traveled the streets with a young sister, holding hands to ward off the chilly air and sometimes exchanging shoes because one pair was cut up and cold.

A whore’s career was usually short-lived. Women who began selling their bodies at age 20 often stopped when they turned 30 just because their looks started to fade. Men who had known them for years tired of them. Younger hookers stole their business. The biggest reason for leaving “the game” was that many women wanted to become “normal,” to marry and have a family, and could not do that while living in a house of ill repute.

Madams’ careers never ended, though, and were often prosperous. The high-class madams kept beautiful brothels. Johns entered the home through a lobby and went to a large living room, where they met the women of the house, chose one and sat back to listen to a woman play a piano. Madams of some of the more luxurious houses earned $1 million a year, in today’s money, and paid no income tax. Some, such as Maria Williamson, owned half a dozen houses of prostitution. Others, like “Princess” Julia Brown, legendary for playing the piano at her brothel, were frequent guests at parties and receptions hosted by the finest families in town. Brown paid for pews at different churches in the city, had season tickets to two different theaters and contributed heavily to local Bible societies.

Sometimes the life of the hooker-turned-housewife was reversed. Many working-class housewives in the pre-Civil War era moonlighted as hookers to earn extra money that they thought was needed to run their homes, buy groceries and keep their children clothed. Some of their husbands urged them to do so. Hundreds of them bought provocative dresses, walked the streets, procured johns and took them to rented rooms in boarding houses for sex.

Some women from other states moved to New York temporarily, usually in the summer, and rented rooms where they turned tricks for a month or two before going back home.

Ironically, hotel owners, even the managers of the most elegant establishments in the city, did not mind having brothels nearby or prostitutes walking their streets. It was good for business. Many out-of-town businessmen staying at the hotels sought prostitutes, and hotel employees provided them.

The police were part of the street hooker’s life. She would pay police, possibly with money from her madam or pimp, to act as an escort to meet men recently arrived in New York and staying at hotels. The constable would meet men in the lobby and ask them where they wanted to go. They would talk about “fun,” and the officer would take them to the Battery, or some other park, and introduce them to hookers he worked with. The officer would go with the john to the door of the hooker’s boarding house and then leave the two alone, with a wad of bills in his pocket.

The constables also did a marvelous job of looking the other way when hookers and wild parties were involved. Whenever a watchman passed an illicit party at a brothel or boarding house, he would not stop to arrest the hookers or the gamblers running illegal games inside. He would merely rap on the door with his wooden nightstick, as a reminder to keep the noise down, and move on down the street, blissfully ignorant.

Prostitution was illegal in New York state and had been for generations. Nothing stopped the world’s oldest profession, though. The “whoreocracy,” as many jokingly called it, prevailed after the city began its population boom in the 1820s, and by the early 1840s New York was the prostitution capital of the United States. “New York is the Gomorrah of the New World,” said Norwegian visitor Ole Raeder.

Illegal prostitution was on the waterfront and everywhere else, promoted by an odd assortment of new journals that plowed an unusual path into steamy sex and criminality — the “flash” newspapers.

The “sporting” or “flash” newspapers, such as the Whip and Satirist of New York and Brooklyn, the Libertine, the Weekly Rake and the Flash, printed long lists of brothels, and short reviews of them, for their readers, men about town who were referred to by all as “sporting men,” or pleasure seekers. These pages always included the address of the brothel, descriptions of its women and the services they provided and, at times, what it cost to enjoy the feminine charms of the employees.

The writers for these papers also wrote evaluations of the hookers they encountered on the street and in city parks. The movement of a prostitute from one brothel to another was reported. There were columns on prostitute balls held in brothels, notes on prostitutes’ fashions and stories about seduction cases that landed in the city courts. The papers resembled today’s Fodor’s guides for travelers.

The New York papers and the sex guides in them were not a dirty little secret, either; they were sold openly at newsstands. They had no authentic news but wallowed in the world of illegal sex at that time. They were even illustrated with bawdy sex cartoons and illustrations.

Illegal prostitution was on the waterfront and everywhere else, promoted by an odd assortment of new journals that plowed an unusual path into steamy sex and criminality.

Police magistrates saw sex cases as trivial, just part of the hooker landscape. In addition to the “victimless” crime of soliciting, using and paying prostitutes, violent crimes were committed against the women. They were sometimes beaten, raped or killed. Many were raped on orders of pimps and madams to make them submissive, to keep them in line, and to force them to work harder in the brothel. New York City’s prostitution corps sustained dozens of brutal rapes in the 1830s and 1840s, some reported to the courts and most not.

The harlots all paraded into court to contest any criminal transgression against them and, often with lawyers, insisted on time-consuming trials. The beatings of hookers by angry clients climbed as the years went by, and each time a girl was hurt she went to court. Numerous prostitutes stood before judges with bumps and bruises to prove assault. They cursed and screamed and every day, added to the list of crimes committed in Gotham. (Helen Jewett herself had taken abusive clients to court in 1833 and 1835.)

And why should constables go after hookers? In 1826, one constable evicted a hooker from a theater where she was trying to solicit business. A crowd gathered outside the theater and hooted and jeered at the constable for doing his job.

Some ladies of the evening fought back. In 1843, a hooker who was shoved by one of her clients on the steps of the Astor Hotel drew a sharp knife from the pocket of her dress and stabbed him in the chest.

Another prostitute fired a revolver at a drunken man in the parlor of her brothel when he tried to attack her. In 1841, one prostitute, Mary Ann Rogers, was sent to prison for beating up another prostitute on a street corner.

Constables told judges and city officials that the force was not large enough to oversee the whores and robbers in a large city like New York.

Almost all of the women charged with working for a madam in a high-end house of ill repute were let go, but most of the street walkers and teenage slum hookers were imprisoned. Incarceration was a regular part of their job, and many had spent months in jail (the usual sentence was 60 days). Reformers visited hookers in the Tombs and other jails every Sunday to try to dissuade them from a life between the sheets.

The reformers noted in their reports, too, that the prostitutes who were in jail for the first time learned all they could about sex from the experienced prostitutes they met there. Imprisonment turned out to be not a punishment but a “college” in which to learn how to make more money through sex.

The whores also told reformers that they lived in a caste system in which some were considered the upper crust of their profession and others the cellar dwellers.

“The women who usually frequent the theater may be said to be of the second class of courtesan, in as much as they are looked down upon by the first-rate women [hookers] who ride about in the carriage of rich protectors,” wrote the editor of the Whip in 1842, adding: “The well dressed evening street harlot looks even with pitiable contempt upon the ragged, low-life creatures who wander the street for the same purpose as herself.”

From “Law & Disorder” by Bruce Chadwick. Copyright © 2017 by the author and reprinted by permission of St. Martin’s Press.