This study examines the nature and intensity of collective action in five Central American nations during the period 1950-1980. Using a historical comparative analysis, I found that Guatemala, El Salvador and Nicaragua have had guerrilla movements and Honduras and Costa Rica have not. Instead, Honduras and Costa Rica have developed workers and peasant movements that are important political forces in their respective societies. These differences are explained by comparing and contrasting the five countries in terms of distribution of land and income, their political structure and their political influence of the United States. Unequal distribution of land and income is commonly thought to produce frustration and discontent, and in turn, higher frequencies of collective action. In Central America, land and income inequality have remained, for the most part, constant, while the nature and intensity of collective action varies over time and across country. Consequently, I concluded that inequality alone does not facilitate the origin and development of forms of collective protest. More compelling theoretical arguments can be made for the political structure of each country and the political influence of the United States as preconditions for the nature and intensity of collective action. The strength of worker and peasant organizations, and their ability to protest non-violently during these times, occurred when the United States encouraged democratic government in these nations. These forms of governance provided freedom and protection for organizing and collective protest. But as the United States supported and encouraged repressive governments, non-violent actions were repressed, and in turn, violent forms of protest originated. Then guerrilla movements appeared and developed when the United States reduced or withdrew military assistance to these repressive governments.