Originally Posted by
titan55
What would be the best way to go through with this then? Would American Airlines be okay with checking in my luggage only to LAX and not SEA (even if the ticket says I'm going to SEA)?
The airline would not do that.
To answer your "best way" question -- (1) carry-on luggage only; or (2) separately ship anything too big for carry-on, to wherever you want it to go in Seattle, via UPS or a baggage service.