The U.S. has controlled a number of different territories over the years. A territory by definition is any area which is not part of a state but still controlled by the federal government. Most of the modern U.S, with the exception of the 13 original states, was a one point a U.S. territory because it did not meet the requirement for statehood upon acquisition.
As far as overseas territories are concerned, the U.S. never really owned nine at once, but I will mention all the areas that were once owned by the U.S. as territories that aren’t part of the lower 48 states;
- Alaska: Purchased from Russia in 1867.
- Hawaii: Annexed by the U.S. after a coup in 1898.
- Puerto Rico: Acquired in 1899 after the Spanish-American War.
- The Philippines: Acquired in 1898 after the Spanish American War. Granted full independence in 1946.
- Guam: Acquired in 1899 after Spanish-American War.
- The Northern Mariana Islands: Became a U.S. Commonwealth in 1978.
- The U.S. Virgin Islands: Bought from Denmark in 1917
- American Samoa: Acquired in 1898 after the Spanish-American War.
There are other areas that were at one point “controlled” by the U.S. military, but were never transferred to federal control. These include Nicaragua, Cuba, Haiti, parts of Japan, Panama and so on. You might have mistaken one of these for a territory, perhaps Guantanamo, but none of them ever were.
You might also argue that Palau or Micronesia were territories, but both were granted independence.