This chapter argues that the 1860s in the Americas witnessed a democratic crest of a largely unrecognized wave of democratic and republican progress, followed by an antidemocratic wave, much influenced by the monarchism explored in the other chapters in this volume. During this democratic crest, American republicanism was seen as in a global contest with the forces of monarchism, the US Confederacy, slavery, and imperialism. The French invasion of Mexico helped to crystallize two visions of modernity and politics, not only in Mexico but also across the Atlantic world, contrasting European imperialism and monarchy with American republicanism. However, by the 1880s, an antidemocratic wave swept across the Americas; although monarchy was not largely revived as a viable political option, many of the monarchists’ values had triumphed. We cannot understand monarchism and antimonarchism in the Atlantic world without exploring the webs of meaning, the imagined alliances, and the connotations with which monarchism was invested.