14 Dec 1864–1 Aug 1868Paraguayan offensivein Mato Grosso
Jan 1865Peru and Spain signshort-lived treatyof cooperation
Mar 1865Paraguay declareswar on Argentina
13 Apr–5 Aug 1865Paraguay invades Corrientes& Rio Grande do Sul
May 1865Brazil, Argentina & Uruguayform Triple Alliance
May 1865Pres. Johnson declaresend of American Civil War
Jun 1865Brazil defeats Paraguayanriver fleet on the Riachuelo