It was not invented but selected it started on May 1866.
May 1, 1866 fell on Tuesday.
May 1866
May 1866 in Waterloo NY
May 5, 1866 in Waterloo N.Y.
Probably several things, but you may be thinking about the nickel (5 cent coin).
16 October 1866 was a Tuesday.
June 10, 1866 fell on a Sunday.
It was started at 9,May 1914
1866
It started in the U.S.A , in1866 I think.
The year Canada started-1866