I am flying from Chicago to LAX. I already have a flight booked from LAX SYD on Qantas. I'm looking for a US carrier that will allow for my baggage to be checked through without my having to exit the secure area of the airport to claim and recheck it.

I tried calling a few carriers (United and American because I prefer nonstop and Southwest is a definite no) and the folks on the other end of the phone were less than knowledgeable. Finding the info on the airlines' sites was also challenging.

Any suggestions would be helpful.

Thank you!
jen