When Argentina declared its independence in 1810, Paraguay refused to join it and instead declared independence a year later. Tension built between the two countries through the early 19th century. When Paraguay tried to invade Uruguay in 1865, Argentina and Brazil came to Uruguay's aid. The war that ensured devastated Paraguay and set them up for being one of the least powerful nations in South America. While large cities in South American usually have reliable transportation, the vast country sides are often only accessible by traveling on the ocean or on one of the country's rivers.
Water transport is still a vital part of trade in many places.
This can be an economic disadvantage to countries without ocean access. Brazil differentiates itself in that it was conquered by the Portuguese while most of the rest of the continent was controlled by Spain. There were so many disputes between the two powers that in 1494, the pope signed a treaty dividing the continent in two. It left Brazil in the hands of the Portuguese who ruled until 1822. Ecuador maintains control over many islands, among them the Galapagos.