The United States Virgin Islands (technically called the “Virgin Islands of the United States”) have used regular U.S. stamps (and currency) since being purchased by America in 1917. Before then, these islands were the Danish West Indies, and special stamps were issued for use under that name by Denmark. Thus, collectors of US Virgin Islands stamps tend to collect covers (envelopes and postcards) sent to and/or from the USVI. These can include American stamps or the Danish pieces.
Collecting US Virgin Islands stamp covers can mean postally sent items that bear postmarks relating to the islands, a fun collectible to hunt for. Also, the islands may appear on stamps and philatelic collectibles from other countries, as a design subject. These interesting items may include air post pieces, first day covers, and other interesting things.
See also: Cuba rare stamps for philatelists and other buyers
Online sellers routinely list a large array of rare and collectible, or otherwise interesting, US Virgin Islands stamps. Check current listings and be aware that the selection changes constantly.
