Granted, I did not spend a lot of time doing legal research but here is a link that shows that tramadol is a non-scheduled prescription only drug under Federal law. The various states may have differing laws, rules and regulations.
Edited to add the FDA link showing it is RX and not OTC. It is NOT a scheduled (controlled) drug but it IS a regulated, i.e. RX needed to buy it legally. No federal penalty for possession. State laws may vary.