Belligerents:

Brazil, Uruguay, Argentine Republic.
Paraguay.

Cause:

Brazil was part of the Portuguese possessions until 1822, when it declared its independence. The Emperors Pedro I and II had frequent trouble not only with the republican movement in Brazil itself, but with the neighbouring states, with whom they were constantly at war. In 1855 Pedro II sent a squadron up the Parana to adjust several questions outstanding with the republic of Paraguay. Although certain rights were granted to Brazil the Government of Paraguay threw every obstacle in the way to prevent a settlement.

Occasion:

In 1864 Lopez, the ambitious dictator of Paraguay, without declaring war, captured a Brazilian vessel, and invaded Brazil and the Argentine. Uruguay joined them in a triple alliance of defence against Paraguay.

Course of the War:

Owing to the strong natural position of Paraguay, and the obstinacy of Lopez, the war was drawn out with constant fighting and great sacrifice of life in addition to vast expenditure, until 1870, when it was terminated by the capture and death of Lopez.

Political Result:

External troubles ceased, but the republican movement gained in strength until 1889, when Pedro was deposed and a republic declared in Brazil.

Remarks:

The slaughter in this war was so terrific that the population of Paraguay was reduced from 1,337,439 to 221,079.

This is only one example of the very frequent disturbances, both internal and external, in the South American continent during the course of the century.