1 Peso Estado Libre y Soberano de Mexico

During the Mexican Revolution, individual states — cut off from federal financial infrastructure and desperate for a circulating medium — began printing their own paper money. Oaxaca, operating as the Estado Libre y Soberano, was among the most prolific of these regional issuers in 1915, producing notes across multiple denominations as Carrancista and Villista forces competed for territorial control and federal currency became effectively unusable across large parts of the country.

The S-prefix in the Pick reference places this squarely among Mexico's vast revolutionary state and local issues — a category so large and poorly documented that attribution disputes remain common.