Puerto Rico is a territory of the United States. It became a U.S. territory in 1898, when it was acquired from Spain after the Spanish-American War. With approximately 3.7 million residents, Puerto Rico is the most highly populated of all United States territories. The power of Congress over territories is exclusive and complete, as described under Article IV of the Constitution:
The Congress shall have the power to dispose of and make all needful rules and regulations respecting the territory or other property belonging to the United States.
A piece of land belonging to the United States can be only a territory or a state under U.S. law.
Why are people sometimes confused over whether Puerto Rico is a territory?
Some people claim that a law passed by Congress in 1952 changed Puerto Rico’s Constitutional status from a territory to a “Commonwealth.” The term “commonwealth” has no special legal status in the United States; for example, Kentucky is a commonwealth and also a state, but this doesn’t make Kentucky different from Louisiana in its relationship to the Federal Government. Read more about this issue.
Read original authoritative sources confirming that Puerto Rico remains a territory of the United States.