"The White Slavery Panic."

The full article with all the involved history, at the link, was pretty fascinating.

Reason Magazine - The 'White Slavery' Panic:

"In 1907 a group of evangelicals visited Chicago’s Everleigh Club brothel, where they handed out leaflets that said, “No ‘white slave’ need remain in slavery in this State of Abraham Lincoln who made the black slaves free.” According to the Illinois poet Edgar Lee Masters, an Everleigh Club regular, “the girls laughed in their faces.”

In Sin in the Second City, the Atlanta-based journalist Karen Abbott recounts how Minna Everleigh, one of the club’s proprietors, “explained graciously, patiently, that the Everleigh Club was free from disease, that [a doctor] examined the girls regularly, that neither she nor Ada [Everleigh, her sister and co-proprietor,] would tolerate anything approaching violence, that drugs were forbidden and drinks tossed out, that guests were never robbed nor rolled, and that there was actually a waiting list of girls, spanning the continental United States, eager to join the house. No captives here, Reverends.”

The Everleigh Club was an ornate mansion. Thirty themed boudoirs (“the Japanese Parlor,” “the Moorish Room,” “the Egyptian Room”) included absurd touches of decadence, such as hidden buttons to ring for champagne and a fountain that fired a jet of perfume. The city’s finest chefs prepared the women’s dinners. They read poetry by the fire with guests, who included the writers Theodore Dreiser and Ring Lardner. Sometimes Minna and Ada let swarms of butterflies fly loose throughout the house.

Some anti-prostitution activists nevertheless believed the Everleigh ladies were no different from slaves. Then as now, opponents of prostitution assumed that no woman in her right mind consensually exchanges sex for money.

...Karen Abbott’s book suggests that prostitution was better respected a century ago. While today’s high-profile johns hold press conferences at which they ask the public for forgiveness, Everleigh Club clients boasted of their membership. Perhaps prostitution was considered a necessary evil, keeping husbands from defiling their wives with their prurient fantasies. Or perhaps, as the Chicago Tribune suggested in a 1936 article about the Everleighs, people believed respectable women “were safer from rapes and other crimes if open prostitution was maintained and ordered as an outlet for the lusts of men.” Patronizing as that viewpoint might be, it is no more insulting than the implication that women never consent to sex work.

Just as feminists today rally around anti–sex trafficking measures, many anti–white slavery activists at the turn of the 20th century were politically progressive and believed in women’s suffrage. “White slavery gave women a chance to insert themselves in political discourse,” Abbott notes. “America’s women would best know how to protect America’s girls.” But such activism infantilizes women instead of promoting gender equality. Women don’t need protection from their own choices. "