There have been caches of roman coins found in the US (google Ohio, when they were blasting for a bridge) Also, some wash up on the east cost shoreline from time to time.
But, it's rare. I'd go back to the site you found it and search more, every square inch!!!
The coin in my avatar was found in a cave in NY about 45 years ago. It's been said tho (by D. Sear) that's it's a copy from the late 1700's to early 1800's. It fooled all other experts of ancients, so I hang on to it just in case (and hope, lol)
Awesome find. I hope you find more!