Do I need to be at the airport 1 hour or 2 hours prior to flight time for a trip to St. John? I can't find anything on the US Air webpage and I've been on hold forever! Is the US Virgin Islands considered domestic travel?

Honestly, with the security at airports the way it is today, an hour is not enough anymore at an airport (and it all depends on what airport you're flying out of). An hour is enough only if you're traveling by yourself and not checking any luggage.
Having read your other posts, sounds like you are checking luggage and that there's more than 2 people on this trip.
My husband and I (with our little one) always do 1 1/2 hours on trips to the Caribbean from Newark airport. That's what we did last year going to St. Thomas and it was just fine.

Thanks Caribtraveler! That sounds like a safe bet to me.

Definitely allow time on the return from St. Thomas to the US. St. Thomas is a port of entry and everyone goes through customs there. The lines can be long depending on the number of flights departing.

We flew Delta and it was confusing too whether St Thomas was considered domestic or international. I got conflicting answers. Finally, I just decided to play it safe, and be at the airport two hours before our departure. Same with our return flight from St Thomas, customs was slow. But the two hours worked fine, with plenty of time to spare. I had heard that we should be there three hours before departure, but that sounded like overkill to me, and I risked it with two hours, and all went smoothly. Have fun.