20 Dollars

Perkins, Bacon & Co. were the dominant force in security printing for colonial issuers throughout the mid-nineteenth century, and the Bank of British North America leaned heavily on them for exactly the reason any issuer did: their patented siderographic transfer process made plate duplication — and therefore counterfeiting — extraordinarily difficult. The "184x" dating indicates the specific year within the decade was not recorded or has not been confirmed, a common documentation gap for early colonial private bank issues.

The Bank of British North America was chartered in London in 1836 and operated branches across British North America simultaneously, which created persistent headaches around note redemption across jurisdictions long before Confederation rationalized the currency system.