There are no remaining possessions or protectorates that are not islands when it comes to the United States. The US actually does not have any possessions that are not in the continental US at this time.
The islands consist of
Puerto Rico
Caribbean Islands
About 700 islands
The Philippines are nearest to Guam.
The collective noun for islands can be a sting of islands, a chain of islands, a cluster of islands, or a group of islands.The word archipelago is not a collective noun, it is a synonym for a group of islands.
Pureto rico
Panama Canal zone and Alaska.
cuba
cuba
Guam
Puerto Rico
Yes, there are two separate Islands- and both issued stamps and were/are British protectorates or colonies.
Caribbean Islands
In addition to the State of Hawai'i, the Commonwealth of Puerto Rico is an island, as are the territories of the American Virgin Islands, and protectorates (Guam, Marshall Islands, etc) and millions of other islands.
The islands, formerly Danish possessions, were sold to the USA by Denmark in 1916.
St, Thomas, St. John, and St.Croix
Alaska and the Midway Islands