Patagonia was regarded as terra nullius by Britain and France until 1881 (and thus shown as a separate state in most maps of the period). Their main concern, shared with the United States, was to prevent any nation restricting navigation through the Straits of Magellan.
In retaliation for Peru’s refusal to pay an indemnity, Spain landed 400 marines to occupy the Chincha Islands—at the time the principal source of Peruvian guano and responsible for almost 60% of the government’s annual revenue. Meeting little opposition, the invaders quickly arrested the islands’ Peruvian governor and raised the Spanish flag. Spain also initiated a blockade of the major Peruvian ports, disrupting commerce and causing resentment across Latin America.
in wikipedia
On 10 August 1864, after negotiations failed to resolve cross-border lawlessness with Uruguay, the Empire of Brazil announced that it would intervene in Uruguay to resolve matters. Brazilian warships were immediately deployed up the Uruguay River, but it was not until October that the Brazilian army was organized enough to launch its invasion, capturing the eastern town of Melo in support of Uruguay’s exiled former-president Venancio Flores and his Colorado Party. Crossing the country, the Brazilians took Paysandú after a month-long siege, then advanced on Montevideo. In February Uruguay’s governing Blanco Party agreed to capitulate, restoring Flores to power.
in wikipedia
In response to Brazil’s invasion of Uruguay in the face of Paraguayan objections, President Francisco Solano López of Paraguay ordered the seizure of Brazilian shipping on 11 November 1864, severing diplomatic relations with Brazil three days later. The next month, on 13 December, Paraguay formally declared war on Brazil, beginning the 6-year-long Paraguayan War, also called the War of the Triple Alliance. Despite the huge population imbalance—Brazil had 9 million people vs Paraguay’s 1 million—Paraguay started the war with over 60,000 trained troops, far greater than Brazil’s 18,000 (or Argentina’s 8,500).
in wikipedia
