4 Reales

The Banco Argentino was one of several provincial banks operating in Rosario during the 1860s, a period when Argentina's interior provinces were still asserting financial independence from Buenos Aires. The denomination itself — reales rather than pesos fuertes or the decimal peso — reflects a transitional moment in Argentine monetary practice, when Spanish colonial units of account were still in everyday use alongside newer nomenclature.

The American Bank Note Company printed the series in New York, which was standard practice for South American issuers seeking security printing of sufficient quality to deter forgery in markets with limited technical infrastructure. The Banco Argentino failed within a few years of issuing this series, sharply limiting total circulation.