1 Peso

The Banco Nacional was established in 1826 under Bernardino Rivadavia's presidency as part of an ambitious — and ultimately short-lived — centralist project to modernize Argentine finance. The bank collapsed in 1836 under the weight of excessive note issuance and government borrowing, and most of its paper was redeemed or destroyed during the subsequent monetary reorganization under Rosas.

The "Caja de Buenos Aires" designation distinguishes notes payable through the Buenos Aires cashier's office specifically, reflecting the federal tensions of the period. Survivors from this early issue are genuinely rare — very few examples are documented outside Argentine institutional collections.