Noble families, granted control of Brazil by the Portuguese king, held the coastal area of Brazil which was divided into 12 "captaincies", each forming an almost independent territory. Expansion inland is made by the bandeitantes, armed bands of free settlers who had escaped control of the dominant nobles and owed allegiance to no one. They were similar to the backwoods settlers of North America. They made raids to capture livestock and slaves. Their settlements eventually pushed into areas claimed by Spain. Gold finds in Minas Geraes in 1693 and in Matto Grosso in 1720 led to a serious Portuguese expansion into the interior of Brazil. Natives were killed, enslaved or pushed off their lands. Portuguese land owners, as well as some Spanish supporters, put pressure on the Spanish colonial government to eliminate the Jesuit missions which provided protection for the natives.
Yellow fever was an uninvited "guest" brought to the Americas on the slave ships from West Africa. Yellow fever is caused by a virus spread by the bite of a species of mosquito native to West Africa, the aedes aegypti. This mosquito was accidentally carried across the Atlantic in water barrels on the slave ships. Yellow fever struck communities from New York to Rio de Janeiro, but aedes aegypti flourished in tropical zones. The mosquito, and with it yellow fever, spread rapidly throughout the Amazon River valley. The disease was so lethal to Europeans, who had little immunity to it, that mass settlement of the Amazon region was not possible until present times.
In 1767, the Jesuits are expelled from South America. Since 1607, the Jesuit order had run missions on the frontier of the Spanish empire in South America. The Spanish were content to stay in the coastal and mountain areas of Peru and Chile. The jungle frontier was mostly left to the Jesuits. The missions were, perhaps, most successful among the Guarani people of Paraguay. They set up workshops and imported the best available tools from Europe. In the missions, Guarani people learned numerous European trades and crafts, including sculpture and painting. The Guarani became accomplished masters of the European baroque art style. One early example of this cultural blend is found in the beautiful sculptures that still exist in the ruins of 17th century missions. The Guarani were not just copiers, but combined European techniques with traditional themes, their love of the landscape, plants and animals of their homeland.
The missions survived in spite of repeated slave raids from Brazil. The Guarani were taught how to govern themselves and be economically self-sufficient through farming and metal working. The Guarani were printing books on art, literature and school texts before the American Revolution in 1775. There were 57 settlements in Paraguay in 1767, but that year, with the permission of the Spanish government, Portuguese and Spanish slave owners were allowed to go in and destroy the Jesuit missions. That stopped the growth of a Guarani nation that might have developed into the first democracy in the Americas.
The native peasant revolt of Juan Santos Atahualpa in the central Andes is put down in 1742. Another native revolt, led by Tupac Amaru, called the last Inca, lasted three years, between 1780 and 1783, before it was crushed. Both revolts were based on a return to Inca rule, culture and economy, and an end to the dominance of Peru by the wealthy Spanish land owners.