There is no good way in one lecture to do justice to the diverse and complex histories of Latin American peoples during these years. I have left out a lot and can only encourage you to do more digging on your own.
Some trends or patterns in Latin American history should be emerging now. First, we see that the commodities boom that accompanied the large waves of industrialization in Europe and the United States brought huge amounts of money into Latin America. Often this money went to very few people; in Mexico, for example, only 3% of people owned land. Often, Latin American profits were funneled back into the United States or Europe through corporations. This left vast disparities of wealth throughout the continent, disparities between rich and poor, between urban and rural, between foreign and local. Second, this economic neo-imperialism was supported by a class of oligarchs who dominated national politics and kept the people in line through a combination of outright repression and meager social programs. This tension between the people and the oligarchies, which were backed by military units with modern weapons, created the setting for widespread unrest throughout the continent. The first and largest revolution occurred in Mexico, costing one million lives and decimating millions of acres of arable land. Violence and political instability was exaggerated by the influence of foreign money and the intervention (as in Central America) of U.S. forces. Third, throughout this phase of Latin America’s history, we see a transformation from economically “liberal” oligarchies to nationalist movements based on vague populist notions. What we don’t find here is the nurturing of a robust democratic political culture. Finally, we see in Latin America similar trends that we have seen in other areas of the world: increased industrialization, urbanization, the rise of a middle class, and the creation of an intelligentsia of writers, artists, and journalists. We see the development of a professional class, a leisure class among Argentines and Brazilians. When we discuss Latin America again it will be in the 1930s, following the Great Crash. We will come to learn how this fractured and transforming society reacted to this incredible economic and social strain.