Originally Posted by transpac
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As a U.S. citizen leaving the country, and then returning, what articles am I importing? Everything in my possession including the items I took with me when I left the U.S.?....
Exactly correct. This is why it is recommended that before you go abroad carrying valuables, you pre-register them with customs before leaving the US, so upon your return, you won't run the risk of being accused of importing the goods and being forced to pay duty on what you already own.