Customs in the US

Immigration and customs is generally handled at your first point of entry into the US. In your case Charlotte. You will need to get your checked bag. Some airports have a baggage recheck facility just after you clear customs.

The exception to this rule is that there are some foreign airports where you can preclear. Vancouver Canada, Bermuda and others.

Edit. Perhaps recheck was a poor description. Baggage drop might be more appropriate

You normally retrieve your luggage in the airport where you first land and then re-check it.

It’s not even really like you recheck it. After finishing immigration, you collect your bag from the carousel, walk through customs and then put your bag back on the carousel. You don’t interact with airline staff at all when putting your bag back on the carousel.

It’s been a couple years since I’ve done this (I’ve been lucky with direct flights or connections in my destination country) but this type of rechecking isn’t like going back to the counter and standing in line with people getting on their first flight etc. After passport control you retrieve your bag and then just hand it back over quickly, no lines and the bag is already tagged. At least in my experience, including once at CLT.
Then you go back through security to get to your domestic flight.

Unless you buy a lot of expensive goods abroad, customs is a non factor when returning to the US. It will be after Immigration, passport control.

Luckily, when you land in SFO, it's just a domestic flight and you can head out quickly.

Went thru customs at Charlotte a few weeks ago coming out of Rome with a final destination of Chicago. Customs, no problem out the door and right there were few good men who took the two bags an off we went to the next flight. Charlotte is an easy airport compared to O'Hare.

TravelLady, but you still had to go through security after having access to you checked bags, right?