I have seen photos of post-Civil War state militia officers wearing
Prussian style helments (the uniform of the Mississippi Natchez
Fencibles being the one I can name off hand).  Perhaps checking for
local militia unit histories will reveal the original user of the
helmet.

Kimo Tichgelaar
----------------------------------------------------------------"Outside
of a dog, a book is man's best friend.  Inside of a dog, its too dark to
read."     Groucho Marx