What three groups had power in Latin America and why?

Ethnic groups. In addition to the foregoing groups, Latin America also has millions of tri-racial peoples of African, Amerindian, and European ancestry. Most are found in the Dominican Republic, Colombia, Costa Rica, Panama, Venezuela, Puerto Rico, Brazil, and Peru with a much smaller presence in other countries.

After three centuries of colonial rule, independence came rather suddenly to most of Spanish and Portuguese America. Between 1808 and 1826 all of Latin America except the Spanish colonies of Cuba and Puerto Rico slipped out of the hands of the Iberian powers who had ruled the region since the conquest. The rapidity and timing of that dramatic change were the result of a combination of long-building tensions in colonial rule and a series of external events.

The reforms imposed by the Spanish Bourbons in the 18th century provoked great instability in the relations between the rulers and their colonial subjects in the Americas. Many Creoles (those of Spanish parentage but who were born in America) felt Bourbon policy to be an unfair attack on their wealth, political power, and social status. Others did not suffer during the second half of the 18th century; indeed, the gradual loosening of trade restrictions actually benefited some Creoles in Venezuela and certain areas that had moved from the periphery to the centre during the late colonial era. However, those profits merely whetted those Creoles' appetites for greater free trade than the Bourbons were willing to grant. More generally, Creoles reacted angrily against the crown's preference for peninsulars in administrative positions and its declining support of the caste system and the Creoles' privileged status within it. After hundreds of years of proven service to Spain, the American-born elites felt that the Bourbons were now treating them like a recently conquered nation.

In cities throughout the region, Creole frustrations increasingly found expression in ideas derived from the Enlightenment. Imperial prohibitions proved unable to stop the flow of potentially subversive English, French, and North American works into the colonies of Latin America. Creole participants in conspiracies against Portugal and Spain at the end of the 18th and the beginning of the 19th century showed familiarity with such European Enlightenment thinkers as Thomas Hobbes, John Locke, Montesquieu, and Jean-Jacques Rousseau. The Enlightenment clearly informed the aims of dissident Creoles and inspired some of the later, great leaders of the independence movements across Latin America.