20 Pesos El Banco Nacional de Mexico

El Banco Nacional de México was the product of a merger engineered in 1884 between the Banco Nacional Mexicano and the Banco Mercantil Mexicano — a consolidation pushed by the Díaz government to create a single privileged institution with federal backing and note-issuing authority. That political arrangement gave Banamex a near-monopoly on large commercial transactions for most of the Porfiriato, and notes of this series circulated in both Mexico City and the provinces through correspondent banking networks.

The nearly three-decade date range for P#S259 reflects continuous reissue from the same ABNC plates rather than substantive redesign — a common economy for high-volume issuers working with American Bank Note.