Best way to travel to Knoxville from Baltimore?

My son is interested in this University of Tennessee, but I can’t figure out an affordable way to get there. What is the closest Southwest hub? Anyone here from Baltimore or DC area with any tips?

The closest Southwest hub is in Nashville, about a 3 hour drive to Knoxville.

These carriers serve Knoxville: Delta, American, United, Allegiant.

that just might be a deal breaker. I’m not willing to drive more than 1.5 hours from an airport - and that is stretching it. Allegiant is the only affordable option and their schedule is twice a week flights. I don’t want to be stuck there for 4 days per visit.

Are there other colleges or universities within driving distance of Knoxville that your son might consider visiting? If so, then you could fly in on Allegiant, rent a car, visit UTK, drive to visit the other schools, and then return in time to take the return Allegiant flight.