1902 $20 National Currency Blue Seal Hugh McCulloch 'The Coal & Iron National Bank Of NYC' FR-650 GRaded f15 By PMG. The series of 1902 Hugh McCulloch twenty dollar blue seal national bank was issued by national banks in all fifty states and even in Puerto Rico as well. National bank notes are different from other nationally printed currency in that they are printed specifically for each individual chartered bank organization. This assisted greatly in creating a system of bank notes that were the same across the country. This aided in travelers knowing what they were spending and receiving in change, rather than the times when each bank and state printed their own currency with their own designs. The National Bank Note system was abandoned shortly after the changeover to smaller size notes in 1929, making the third charter notes the last truly used issue of this kind.