I don't know either. I do know the guy has probably had the bill since at least the sixties and possibly earlier. In the 80's when I lived in Mississippi, $500 bills were still in circulation. The lady we dealt with at the bank offered to hold one for us. I never took her up on the offer.
I think at one time the larger bills did circulate. With the rise of money laundrying and the drug problem, the fed has taken everything but $100s out of public circulation.