A territory is part of the United States, but it isn’t a state. The United States has five territories.
- American Samoa
- the Northern Mariana Islands
- Puerto Rico
- The US Virgin Islands
The citizens of Guam, the Northern Mariana Islands, Puerto Rico, and the US Virgin Islands are also citizens of the United states. Congress has never granted citizenship to the citizens of American Samoa.
Each of the five territories has a nonvoting delegate in the House; however, no territory has representation in the Senate.
The citizens of the territories, even though most of them are citizens of the United States, cannot vote for the president.
Generally, citizens of the territories don’t pay federal income taxes. They do pay Social Security taxes.
Citizens of the territories qualify for Social Security, Medicaid and Chip, and Medicare. In Harris v. Rosario, the Supreme Court held that the federal government could provide smaller Medicaid, Medicare, and Welfare benefits to the citizens of the territories.
The military allows citizens of the territories to serve.
Article IV of the Constitution says Congress can make the rules for all US territories. This means that Congress can overrule any law passed by the government of any of the territories. In Granville-Smith v. Granville-smith, the Supreme Court said a divorce law passed by the legislature of the US Virgin Islands violated the authority Congress gave the legislature.
For information about the territories, you should read The Not Quite States of America. I’m reading it now.