Thanks for sending me the pictures. I like the cup. I believe it is French, made in Paris, likely between 1819 and 1838. I haven't been able to identify the maker's mark - the mark with the 2 T's with the quill between. I suggest you upload the pictures to this site so that someone else might be able to identify the maker.
Thanks for the lastest info. The dates are about what I thought. The French attribution makes sense as the cup was found in Louisiana back in the 1960s. How do I upload pics to site?
Regards - Zach
I've identified the maker of your cup as "Theodor Tonnelier" working in Paris after 1798. Go to this page, http://www.925-1000.com/Ffrench_makers_05.html ,
and scroll down until you come to the Tonnelier mark.