Paraguayan naval forces attack the river port of Corrientes and so bring Argentina into their war with Brazil

The aggressive policies of Paraguayan president, Francisco Solano López, together with resistance from Brazil, had brought open warfare between the two nations in late 1864.  To strike at Brazil, Paraguay invaded another neighbor, Argentina, after its president had refused peaceful passage of troops from either combatant. Paraguayan naval units captured Corrientes, an Argentinian port on the Parana River.  This would bring Argentina into a war that would last until 1870 and devastate the region, killing perhaps 400,000 South Americans.  (By John Osborne)