Originally Posted by
Brahmin
I will be traveling from STT to LAX via MIA.
Do I need to clear Customs/Immigration anywhere? I have a US passport.
What about security? Would I have to do that again in MIA?
I am thinking of buying liquor at STT airport and putting it in my carryon. Will this create a problem at MIA?
Your first Q is about "security." You will clear the TSA checkpoint at STT and not again at MIA.
Your second Q is about USA entry. The reason for the entry formalities is due to the USVI's location. Theoretically, CBP could conduct examinations/inspections "at or near the border" anywhere, and does so at STT. As others note, you do not need a passport, but it helps. If you are not a US National, check the CBP website for the exact requirements.