Portal:Argentina/Anniversaries/May/May 20


 * 1591: Establishment of La Rioja
 * 1780: Birth of president Bernardino Rivadavia
 * 1810: Juan José Castelli requests an open cabildo to viceroy Baltasar Hidalgo de Cisneros
 * 1946: Ill with diabetes, President Roberto María Ortiz is replaced by vicepresident Ramón Castillo