The Mann Act was a significant piece of legislation aimed at addressing concerns over the trafficking of women and girls for immoral purposes, including prostitution. Introduced by Congressman James Mann of Illinois, the act sought to curb the rise of vice that was often associated with urbanization and the changing social landscape of the early 20th century United States. The law made it a federal crime to transport any woman or girl across state lines for the purpose of engaging in any sexual activity deemed immoral. The language of the act was intentionally ambiguous, which allowed for a broad interpretation and enforcement.

The passage of the Mann Act reflected a growing concern among reformers about the perceived moral decline of American society during this time. Progressive movements were advocating for various social reforms, including those addressing labor rights, women's suffrage, and social purity. The Mann Act was positioned within this framework as a means of protecting women and girls from exploitation, while also aiming to assert moral standards across a rapidly evolving nation. Its enforcement was often selective and could be influenced by societal norms and prejudices, resulting in the prosecution of individuals who were sometimes targeted not for trafficking, but for their sexuality or lifestyles.

Over the years, the Mann Act led to high-profile legal battles and cases that illuminated the complexities of morality, consent, and state versus federal jurisdiction. Some individuals, including prominent figures in entertainment and sports, found themselves ensnared by the law due to its broad definitions, which were often manipulated for purposes beyond its original intent. This ambiguity not only highlighted enforcement disparities but also opened debates about civil liberties and the role of government in personal affairs, foreshadowing conflicts related to morality and legislation in later decades.