- 02-February-1536 : Spaniard Pedro de Mendoza founds Buenos Aires, Argentina.
- 25-May-1810 : May Revolution: Armed citizens of Buenos Aires expel the Viceroy from Spain and establish a provincial government for Argentina.
- 31-January-1814 : Gervasio Antonio de Posadas becomes Supreme Director of Argentina.
- 09-July-1816 : Argentina gains independence from Spain.
- 19-January-1817 : An army of 5,423 soldiers, led by General Jose de San Martin, starts crossing the Andes from Argentina to liberate Chile and then Peru.
- 12-February-1817 : Battle of Chacabuco: The Argentine/Chilean patriotic army defeats the Spanish.
- 20-February-1827 : Battle of Ituzaingo (Passo do Rosario): A force of the Brazilian Imperial Army meets ArgentineArgentineUruguayan troops in combat.
- 07-March-1827 : Brazilian marines sail up the Rio Negro and attack the temporary naval base of Carmen de Patagones, Argentina; they are defeated by the local citizens.
- 27-August-1828 : South America: Brazil and Argentina recognize the independence of Uruguay.
- 23-July-1881 : The 1881 Border Treaty between Chile and Argentina is signed in Buenos Aires.