A hundred years ago, the United States first projected itself onto the international stage, hoping to stake out a sphere of influence in Latin America just as the largest of Latin American countries, Brazil, ending a 67-year-long monarchical regime, struggled to redefine its relationship to the world economy. Debates raged between liberals and corporatists, between free traders and protectionists. When the trajectories of these two unequal giants collided, their interaction revealed much about the international economic and political affairs of their day that bears upon the debates...