Leading citizens of Buenos Aires meet in 1826, formulate a new unitary constitution and elect Bernardino Rivadavia president.

The provinces do not support the new government, centralized at the expense of the caudillos; Rivadavia’s resignation is followed by two years of civil war between the unitarios and the federalists.

“Tiger of the Plains” Juan Facundo Quiroga, Argentine caudillo, staunch federalist, and the virtual absolute ruler of the Andean provinces, leads the opposition.