Unincorporated organized territories
- Guam (since 1898): also the home of a U.S. Naval Base and a U.S. Air Force Base.
- Northern Mariana Islands: formerly a United Nations Trust Territory under the administration of the United States, it established itself as a U.S. Commonwealth in 1978.
- Puerto Rico (since 1898): established as a U.S. Commonwealth in 1952.
- United States Virgin Islands (since 1927): these were purchased by the U.S. from Denmark, initially in order to add to the defenses of the Panama Canal.