I agree with the consensus here, pretty likely British, and that brass hilt conforms to various British patterns of mid 19th c. typically infantry, and other units officers swords . It is heartening to see photography that makes my own look almost discernible
.......but great post!
It's good to have a Civil War buff around, eh? (my daughter is in Upper State Michigan yooper land).
Thank you for the offers on input on that, thats what its all about here, sharing expertise!