Originally Posted by
mahasamatman
Welcome to FT, nanaof2!
No need to link anything. Just show them your ongoing reservation. The only trick might be the overnight layover, but I think they'll still through-check the bags.
At SFO they don't have bags tagged through. You have to pick them up and go through Custom Clearance then re-check them for your domestic flight. No exceptions that I've ever heard of.
Last I heard that applied pretty much everywhere in the US. First port of arrival you go through Customs even if you have a connecting domestic flight.