Kudos to Moore's Bicycle Shop in Hattiesburg for getting me wheels!
When I explained the situation, the person at the shop, suggested I could buy one of their used bikes which comes with a warranty and a six month buyback at half price (less damages, repairs, helmet, modifications, etc). I chose an inexpensive used bike priced at $179 and a low priced helmet. The bike was in excellent repair and I like it a lot. I got local route advice at no charge.
Actually, my first idea was to head to the pawnshop district and pick up the cheapest bike I could ride away on. What I saw there was depressing. But next door was Moore's Bicycle Shop.
Advance planning is half the solution for travel. The other half is taking advantage of whatever opportunities come along.
Rajman, the idea of mailing the bike beforehand is a very good one. Too bad I didn't think of it! That's a good addition to the bag of tricks.
Roody, I think your evaluations are correct. This trip is purely experimental. I wanted to improve my carfree skills and try out some ideas that are new to me.