This 1968 Chilean airmail stamp commemorates the 150th anniversary (Sesquicentennial) of two decisive battles in South American independence history: Chacabuco (1817) and Maipú (1818). The design features the profiles of two key independence leaders — José de San Martín and Bernardo O’Higgins — whose leadership helped secure Chile’s liberation from Spanish colonial rule. Printed in a striking violet engraving style, the stamp reflects classical portrait artistry typical of mid-20th-century Chilean issues. Produced by the Casa de Moneda de Chile, it was issued for international airmail correspondence. For collectors, this stamp is valued both for its historical theme and its elegant engraved design celebrating Latin American independence.