Hi,sorry the photos are not that sharp.Is this one American?1821 for the date seems impossible,so it maybe the date of the establishing of some whisky?
It doesn't look American, I'm guessing it's European. If it was American then bitters would be my guess, but from Europe it's hard to say. It could still be bitters. 1821 is probably a mold number that wouldn't mean anything to anyone other than the people working in the glass factory. It probably dates to around 1900, give or take a decade or two.
I believe that is a Gin bottle that took a ground stopper. I have one that looks identical I use for mouth wash. Mine has an etched logo and wording in the smooth middle portion.
Jim