AD 395-408 AE2, 4.5g, 22m, 12h Heraclea mint, seventh period Obv.: DN ARCADI-VS PF AVG Diademed, draped, and cuirassed bust right Rev.: GLORIA TOMANORVM Emperor standing front, head right, holding globe and labarum//SMNB
ROMANORUM. Slight typo, there. It happens to me all the time. Cool. You know, I found one of these, once... right here in Georgia! Unsurprisingly, my ground find was much rougher than your piece, though.
Late Roman coins can be found in North America. The Europeans in the 17th-18th c. sometimes used them for trade with the Indians. Hoards of LRBC coins had no value in Europe but could be shipped to the New World.
Yes, I know that. Firsthand. I found one. And that scenario in the last sentence is almost certainly what happened. It came over on the boat, maybe in ship's ballast, likely from England, and probably during the colonial era. Or such is my pet theory, anyway, based upon the other artifacts in the same washout where I found it. It might have done service as a farthing in the 18th century, when small change was desperately needed and few people would have cared enough to save it as a curiosity. It would have only vaguely resembled a farthing of the era- and been a bit too thick- but I suspect few people would have paid much attention to it at the time.