50 Pesos

The Banco y Casa de Moneda del Estado de Buenos Ayres occupied a peculiar constitutional position in the 1850s — it operated as the currency-issuing authority for the Province of Buenos Aires during the decade following the Acuerdo de San Nicolás, when the province had seceded from the Argentine Confederation and was functioning, in practical terms, as an independent state. Notes issued during this period circulated exclusively within the province and were not recognized by the Confederation government in Paraná.

The PS prefix in the Pick reference reflects that ambiguity — these are catalogued as provincial issues, distinct from national Argentine currency, and rightly so. By 1863, following reunification, the bank's note-issuing role was progressively curtailed.