The Commonwealths are self-governing and unincorporated territories of the United States. They are administered directly by the federal government of the United States and they are not part of any US state. This relationship can be compared to the one of a protectorate. Historically they have their origin in three different circumstances: The US government, and Congress in some cases, retains exclusive powers on: On the last three, exceptions are made since 1924 with members and resolutions of the Pan-American Union