Welcome aboard
This appears to be a late 19th century Massachusetts Ancient&Honorable Artillery sword. Some were marked to Allien&Co. of New York. Others by Ames. No doubt, there were likely other groups buying these. These appear in the Ames catalog reprint.
There are multiple threads elsewhere.
A book regarding the society
https://books.google.com/books?id=q5hoNuEJPMoC
This is the Americanized offshoot going back to colonial years and borne out of the English artillery.
Cheers
GC
images with blue background courtesy of Shiloh Relics and a past sale.