Prostitution did not become illegal in the US on any single date. It shifted from loosely tolerated to broadly criminal through a patchwork of local, state, and federal laws passed roughly between 1870 and 1920. For most of the country’s first century, the sex trade was treated as a nuisance to be managed rather than a crime to be punished. The push toward outright prohibition accelerated during the Progressive Era and reached near-total nationwide criminalization by the end of World War I.
What the Law Looked Like Before Criminalization
Through the late 18th and early 19th centuries, almost no American statutes mentioned prostitution by name. Authorities leaned on English common law to keep order in growing towns, prosecuting people in the trade under vagrancy statutes or laws against keeping a “disorderly house.” Those charges targeted the disruption a location caused — noise, crowds, fights — not the exchange of sex for money itself.
Cities took a containment-first approach. Informal red-light districts operated with the tacit approval of local police, and officers often collected unofficial fines or bribes that functioned as a kind of licensing fee. As long as the trade stayed in designated areas, authorities mostly left it alone. Most cases that did reach court ended with small fines or short stays in a workhouse.
Whether the trade was tolerated, ignored, or sporadically cracked down on depended almost entirely on local politics and local police. There was no national policy, no federal involvement, and no uniform criminal statute.
The Page Act of 1875
The federal government first stepped in through the Page Act of 1875. The law banned bringing women into the country for the purpose of prostitution, treating it as a form of forced labor. For the first time, Congress used its authority over immigration and commerce to address the sex trade rather than leaving it to local police.
Enforcement fell hardest on women of East Asian descent. The statute itself specifically referenced China, Japan, and “any Oriental country,” and federal officials interrogated women at ports of entry about their intentions and moral character. Those suspected of being brought in for sex work were denied entry or deported.
The penalties were stiff for the era. Importing women for prostitution was a felony punishable by a fine of up to $5,000 and imprisonment of up to five years.1GovInfo. 18 Stat. 477 – An Act Supplementary to the Acts in Relation to Immigration A separate provision penalized transporting anyone from those countries into involuntary servitude, with a fine of up to $2,000 and up to one year in prison.2Library of Congress. Page Act of 1875 The Page Act didn’t criminalize prostitution inside the states, but it established that the federal government could use its power to try to suppress the trade.
The Mann Act of 1910
The White-Slave Traffic Act of 1910, universally known as the Mann Act, turned prostitution from a local policing matter into a potential federal felony. The law made it a crime to transport anyone across state lines “for the purpose of prostitution or debauchery, or for any other immoral purpose.”3Library of Congress. 18 U.S.C. Chapter 117 – White Slave Traffic That vague “immoral purpose” language gave prosecutors wide discretion and converted what had been a local misdemeanor into a federal felony the moment a state line was crossed.
Original penalties ranged from a $5,000 fine and five years in prison for the basic offense up to $10,000 and ten years for cases involving coercion or victims under eighteen. The statute was sold publicly as a weapon against organized trafficking, but its sweeping language made it useful for prosecuting conduct far removed from commercial sex. Congress rewrote the Mann Act in 1986, making it gender-neutral and stripping out the “debauchery” and “immoral purpose” language. The modernized version now criminalizes transportation with intent that a person “engage in prostitution, or in any sexual activity for which any person can be charged with a criminal offense,” with a maximum sentence of ten years for the basic offense.4Office of the Law Revision Counsel. 18 U.S. Code 2421 – Transportation Generally
World War I and the End of Tolerated Districts
The decade from 1910 to 1920 brought the wave of state and federal action that effectively ended tolerated prostitution in the US. Two forces converged. A morality-driven social hygiene movement pushed for state legislation, and the federal military demanded that cities shut down vice near training camps as the country mobilized for war.
The military angle mattered enormously. The Selective Service Act of 1917 included a provision prohibiting prostitution near military installations, and the War Department’s Commission on Training Camp Activities pressured cities to close their red-light districts or face consequences. The most famous casualty was Storyville, New Orleans’ legally sanctioned vice district, shut down in 1917 on orders from the U.S. Navy. Similar closures swept past bases around the country, and districts closed under wartime pressure rarely reopened.
Red Light Abatement Acts
States began passing Red Light Abatement Acts that gave private citizens and officials a civil tool to shut down brothels. The laws allowed anyone to sue the owner of a property being used for prostitution, labeling the building itself a public nuisance. A court could order the building closed for up to a year and its contents sold to cover legal costs. That approach sidestepped the challenge of criminal prosecution: there was no need to catch anyone in the act, only to prove the building’s purpose.
In the same stretch of years, states replaced old vagrancy and disorderly-house charges with statutes that explicitly criminalized the solicitation and sale of sex. By the end of World War I, nearly every state had such a law on the books. The combination of federal military pressure, new state criminal statutes, and civil abatement laws produced the near-uniform prohibition that still shapes US law today.
The Nevada Exception
Nevada is the only state that permits legal, regulated prostitution, and that fact is worth flagging because readers often assume prohibition is universal. Nevada’s system is codified at NRS 244.345, which lets counties with a population under 700,000 license and regulate brothels.5Nevada Legislature. Nevada Code 244.345 – Dancing Halls, Escort Services, Entertainment by Referral Services and Gambling Games or Devices Counties above that threshold, which include the Las Vegas and Reno metro areas, cannot issue such licenses. Working outside a licensed brothel is still a crime even in counties that allow the licensed version, and only a handful of rural counties host active brothels.
FOSTA-SESTA and the Online Era
The most significant federal expansion of prostitution law in the 21st century came in 2018, when Congress passed the Allow States and Victims to Fight Online Sex Trafficking Act, usually called FOSTA-SESTA. The law was a direct response to websites like Backpage.com, which had become the main marketplace for sex work advertising and had resisted legal action by claiming immunity under Section 230 of the Communications Decency Act.
FOSTA-SESTA made three major changes. It carved out an exception to Section 230, so that the immunity shield no longer applies to federal or state charges related to sex trafficking or the promotion of prostitution.6Congress.gov. Allow States and Victims to Fight Online Sex Trafficking Act of 2017 It created a new federal crime under 18 U.S.C. § 2421A, punishing anyone who owns or operates a website with intent to promote or facilitate prostitution with up to 10 years in prison, rising to 25 years if the operation involves five or more people or shows reckless disregard that the conduct contributes to sex trafficking.7Office of the Law Revision Counsel. 18 U.S.C. 2421A – Promotion or Facilitation of Prostitution and Reckless Disregard of Sex Trafficking And it gave trafficking victims a civil right of action against website operators.
Recent Shifts Toward Decriminalization
After a century of near-universal prohibition, the political landscape has started to move. In 2023, Maine became the first state to decriminalize the selling of sex while keeping buying illegal, an approach often called the “Nordic model.” New York, Massachusetts, and Vermont have introduced similar buyer-focused bills or full decriminalization proposals. None had passed as of early 2026, and no federal decriminalization legislation has been introduced. The debate itself marks a shift from the near-total consensus on prohibition that held for most of the 20th century.