Probably 1700's
That's how it all started for me, I found one in a field then the rest is all history, lol
Nice find, welcome to the site, and keep digging. GL & HH
Brad
Nice button. I don't find them with gilt still on them very often. I think it is later than 1700s though, in my opinion. I would guess 1820s or so, but I am no expert. Very nice button regardless.