Issued by Mexico in 1966, this 80 centavos airmail stamp commemorates the IX Congress of the Postal Union of the Americas and Spain (UPAE), an important organization promoting cooperation among postal administrations across the Spanish-speaking world and the Americas. The design features a ceremonial postal horn, a historic symbol of postal communication, beneath a stylized banner announcing the congress. Printed in a striking red and black two-color design, the stamp also bears the inscription “Aéreo”, identifying it as part of Mexico’s airmail series. The clean modernist layout reflects the graphic style of the 1960s. For collectors, this issue is notable for its postal history theme and representation of international postal collaboration.