The year was 1910 and it marks the entry of the national government into the enforcement of morality laws - most prostitution. It also reflects the nature of attitudes about race at that moment.
I mention this law in sections that cover the increasing power of the national government in areas that had previously been reserved solely to the states. Given that prostitution is a commercial act that can involve commerce over state lines - the national government can claim a constitutional right to lass laws related to it. It's focus also on "immoral purposes" made it a flexible law that could be used for whatever purpose authorities wished.
For some links:
- History.com: Congress passes Mann Act.
- Wikipedia: the Mann Act.
- NPR: The Long, Colorful History of the Mann Act.
Cities in the United States had a large number of brothels up until this time. The passage of the bill was helped by a sudden moral panic that swept the nation that was wrapped up in attitudes about immigrants, the proper social order and the causes of prostitution.
One of the people trapped in the enforcement of the law was Galveston native Jack Johnson who flaunted conventional attitudes about race.
