In the Americas the century or so between independence and World War I was a time of nation building. Colonial governments were overthrown, new constitutions were written, settlement was extended, slavery was ended, and immigrants from around the world settled across the continents. On the eve of World War I, there was reason to be optimistic about the future of all these countries.

World War I, the topic of the next chapter, affected these countries in a variety of ways. Canada followed Britain into the war in 1914 and sent six hundred thousand men to fight. The United States did not join the war until 1917, but quickly mobilized several million men and in 1918 began sending soldiers and materials in huge numbers. Even countries that maintained neutrality, as all the Latin American countries other than Brazil did, felt the economic impact of the war deeply, especially the increased demand for food and manufactured goods. For the working class the global demand for exported foods drove up the cost of living, but the profits that oligarchs accummulated fueled the process of industrialization.