The territories and states listed in this group were at some time, or still are,
linked to the United States of America as trusteeships, protectorates or
dependencies. These were acquired towards the end of the 19th century or
following World War I, and finally as a result of World War II. Territories such
as Cuba, Puerto Rico and the Philippines were not included here, due to the
Spanish nature of most of their stamps. The United States has the largest amount
of `back-of-the-book` collecting items, such as pre-cancellations, revenue
stamps, hunting stamps (duck stamps), etc.