Congress makes it a federal crime to move women across state lines for 'immoral purpose'

By 1910, Progressive Era reformers had whipped up a nationwide panic over "white slavery" — a conspiracy narrative holding that organized networks were kidnapping women off city streets and into forced prostitution. Vice commissions across the country were shuttering brothels and red-light districts, and Congress wanted a federal answer. On June 25, 1910, lawmakers passed the Mann Act — named for Illinois Congressman James Robert Mann — making it a federal felony to transport "any woman or girl" across state lines "for the purpose of prostitution or debauchery, or for any other immoral purpose." The phrase "any other immoral purpose" would prove to be the act's most consequential words…