USA-Jamaica intl. flight with domestic connection--customs question about Atlanta and Miami airports

USA-Jamaica intl. flight with domestic connection--customs question about Atlanta and Miami airports?
I'm flying to Jamaica February 1st and I've only flown internationally once before, to Uganda from Chicago via London Heathrow. This time around, I'm flying to Kingston (JA) from Atlanta via Miami. Obviously, I'll still be in the States for my connection, and my flight from Atlanta to Miami is domestic. As I recall back in Chicago, there were separate security lines for domestic and international departures. My very first flight (ORD-LHR) was international, so I knew right where to go and everything worked perfectly. But this time, my first flight is to Miami though my final desination is in Jamaica. So do I get in the international lines at Atlanta, or do I go to the domestic lines and then go to the international lines in Miami? And I will have to go through security again at Miami, right? That's how it worked in London. Sorry if it sounds like a mundane question, but I want to know what the heck I'm doing before I get there and have to ask someone in my frenzy to make it to my gate. Thanks! :)
Air Travel - 2 Answers
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1 :
Since your ultimate destination is Jamaica, your flight is considered international. As for going through security again in Miami, as long as you do not have to leave the secured areas of the airport to switch terminals, then you should not have to.
2 :
you only go international lines in miami if you have to since you are stil flying domestic