The US has many territories, commonwealths, and protectorates. Guam, Samoa, Puerto Rico, Saipan, US Virgin Islands, and many Pacific islands. Formerly, the US also had possession of Cuba, Panama, and the Philippines. They each existed for useful reasons.
Saipan specifically is basically a place where normal US labor law does not apply, but anything made there can be labeled "Made in USA." It has a huge textile industry, and it's supported by a huge kidnapping/human trafficking industry.
Here's how it works: people in Asian countries like China or Malaysia who are desperate to leave pay a smuggler their life savings to take them to the USA. The smugglers instead take them to Saipan where they are locked in sweatshops to make shoes and shirts for major retailers - if they're lucky. They may also be forced into prostitution to service wealthy US businessmen. The sweatshop owners and pimps pay kickbacks to the smugglers.
The entire economy of Saipan is built around this, and nothing is ever done to stop it because the sweatshop owners pay huge bribes to the powerful families who run Saipan. So the island can't uncorrupt itself, and US politicians receive lots of campaign funds from the retailers who buy their goods from Saipan (former House Majority Leader Tom DeLay famously visited Saipan several times and never found anything he didn't like).
