I sort-of agree with Denny. Since many, if not most States, required front and rear plates it would make sense that the vehicles would come with brackets for both.

When I got my truck, that was produced in Baltimore, it had front and rear YOM 1941 Maryland plates on it. Interesting question nevertheless.

My 1941 in the Stovebolt Gallery
My Photo Album

But I tried, didn't I? ... At least I did that. RP McMurphy
The past belongs to the future...but only the present can preserve it.
Besides the noble art of getting things done, there is a nobler art of leaving things undone.