The Mann Act, named for US Representative James Mann, is also called the White Slave Traffic Act of 1910. The Mann Act makes it illegal to transport a person into or out of a state, territory, or any possessed land of the United States for the purpose of immoral sex or prostitution. This law has been used to prosecute sexual relations between adults and minors, perpetrators of human trafficking, and polygamists. Violation of the law is a federal offense and a felony.
The White Slave Act of 1910 was actually introduced in 1909. Its sponsor was an Illinois Republican named James Robert Mann. The need for the law was based on stories that Chicago had become the home of white women imported into the United States and forced into prostitution. The act was made law in 1910 by President Taft.
The Mann Act was designed to discourage interstate commerce that related to prostitution, debauchery, and immorality. The still law focuses heavily on the movement of individuals. This is because the motivation behind this legislation was to curb immoral sexual activities, although it was deemed that Congress does not have the power to regulate such activities. Congress does, however, have the power to control transportation between states.
At one time, the wording of the Mann Act was vague, and specific crimes were not clearly outlined. Over time, the law has been amended and clarified on several occasions. One of the crimes that is now specifically outlined in the Mann Act pertains to child pornography.
When the law was first enacted, its primary focus was on commercial activities. Eventually, the law became useful for authorities seeking the prosecution of consensual and non-commercial encounters. For example, the term "immoral activities" was expanded to cover polygamy. Including polygamous transportation allowed a man with multiple wives to be prosecuted when driving the women from one state to another or across international borders. Many uses of the law in prosecuting non-commercial and consensual sex are no longer valid; adulterous acts, for example, are no longer prosecuted under this law.
The Mann Act was originally designed for the protection of women. It now includes protection for both sexes and for minors. Since the Mann Act is a federal offense, federal courts have jurisdiction over cases stemming from these laws. Someone prosecuted under this act is charged with a felony, and if convicted, he is subject to incarceration in federal prison.