American Samoa is a contradiction in terms. Since Samoa is not located anywhere near America, how can it be American? You are right, it cannot.
Do not EVER, UNDER ANY CIRCUMSTANCES, try to visit American Samoa. It is extremely dangerous and should be left to professionals only.
American Samoan postage stamps are valued by collectors because of their unusually large size (the size of the stamps, not that of the collectors, stupid!). Each stamp covers an area of six square feet. This is, however, considerably limiting the ability of the American Samoans to communicate by writing letters, since the law only permits standard-size envelopes.