Probably a silly question, but I was wondering why some of the 1902 series National Bank Notes have two different serial numbers while others have a single one.
In my picture below I have two 1902 series blue-seal $10 NBNs, one with dates on back, the other plain back. The first has two different serial numbers, while the other has a single S/N printed twice.
I'm guessing that it was just a transition made when they went to the plain back notes, but wondering if there was a specific reason.
BTW, I just ordered Don C. Kelly's "National Bank Notes" reference to learn more about this series of notes. I'm looking forward to adding it to my library.
