RobertB
Thanks for the input, guys.
I'll check with the airline, to make sure I don't have any surprises at the airport.
Our current plan is to fly into San Francisco, and drive up the coast to Oregon(7 hours). We are looking at an 8 hour layover there anyway, and the drive will be way more fun. Donna hasn't traveled much, so it is a rare opportunity.
Depending on what the airline says about the guitar, I will either ship it from San Francisco to Fort Worth, or carry it onto the plane.
My daughter is getting married. I'm getting an awesome guitar. Donna gets to experience a good part of the Northwest coast for the first time. I haven't seen my sister in years. I am totally stoked. This is going to be good.

VERY cool!  you guys deserve a nice vacation, too!

Yep.... the advice I was going to offer was what Reece said. Ship it UPS or FedEx insured. If it has a case, of course, put it in the case, then put the case in a box and pack it securely. Insure it for the proper amount and ship it. The cost is much less than a seat beside you on the plane.
 
That's how the music stores ship things and they tend to get to where they're going without damage. I'd much rather deal with the UPS/FedEx damage claim dept than the airlines damage repair dept should there be any damage to the shipment. I use UPS a lot and have never really had any problems with lost or damaged items.

If you stop by any decent music store, ask the guitar manager and usually they will give you a Kaman shipping box.  I tend to call ahead to find out when they'll be unloading so I can get one before they flatten it for recycling.