United States national bank notes

United States national bank notes were paper currency issued from 1863 to 1935 by financial institutions holding federal charters under the National Banking Act. Supervised by the Office of the Comptroller of the Currency, issuing banks were required to deposit United States government bonds with the Treasury to back the notes up to ninety per cent of their value, alongside maintaining a five per cent redemption fund in gold or lawful money. Although not general legal tender, they were accepted for almost all federal payments. The currency program was terminated during the Great Depression in the 1930s, when national currency was consolidated into Federal Reserve Notes, United States Notes, and silver certificates.

For most of their history, national bank notes were produced in a large-size format. These early issues prominently displayed the issuing bank's title in shaded type on the obverse rather than identifying the United States of America as the primary heading. Large-size notes bore two separate serial numbers—a Treasury serial number for all notes of that series and denomination, and a local bank serial number. They also featured four signatures: printed signatures of the Register of the Treasury and the Treasurer of the United States, alongside the individual handwritten signatures of the bank's cashier and president. Most showed the bank's charter number engraved within the border and overprinted on the obverse, whilst later issues added regional letters to aid Treasury sorting.

With the adoption of small-size currency in the late 1920s, national bank notes conformed to standardised portraiture and decorative motifs. The bank's name was no longer engraved into the main plate but over-stamped in black ink above the promise-to-pay, and the charter number was overprinted in dark ink. On final small-size printings, known as Type 2 notes, the charter number was additionally printed twice in brown ink aligned with the serial numbers.