In South America, Brazil, Argentina, and Uraguay form the Triple Alliance for their war against Paraguay

The aggressive policies of Paraguayan president, Francisco Solano López, together with resistance from Brazil, had brought open warfare between Paraguay and Brazil and Uraguay in late 1864.  After López attacked another neighbor, Argentina, a few weeks before, the three nations ranged against Paraguay met and formed the Triple Alliance.  Full details of the alliance were kept secret. The war would last until 1870 and devastate the region, especially Paraguay, killing perhaps 400,000 South Americans.  (By John Osborne)