Before the invention of leading zeros as placeholders for numbering small size currency, the handling of low serial numbers was a serious bottleneck in the numbering of currency at the Bureau of Engraving and Printing.
Serial numbering U.S. currency was considered to be an important check on runaway printing of currency by a reckless government as well as a convenient accounting device. Consequently, huge investments in labor and machines were and continue to be made to print a unique number on every note.
Up until 1903, all serial numbers were applied to currency on paging machines operated by women. The machines stamped the numbers onto currency in sheet form one number at a time. Think about this burden. In 1900, the BEP cranked out 100 million pieces of currency. By 1910 that volume ballooned to 300 million. It took
