Before 1861, US Americans could confidently claim to belong to the New World's "exceptional" republic, unlike other self-governing nations in the Western Hemisphere such as Mexico, which struggled with political violence and unrest. Americans used such comparisons to show themselves and the world that democracy in the United States was working as designed. The outbreak of the Civil War in 1861 exploded this illusion by showing that the United States was in fact not immune to domestic political instability. Joining a growing community of historians who study the war in a global context, Alys D. Beverton examines Mexico's place in the US imagination during the Civil War and postbellum period. Beverton reveals how pro- and antiwar Confederates and Unionists alike used Mexico's long history of political strife to alternately justify and oppose the Civil War and, after 1865, various policies aimed at reuniting the states. All used Mexico as a cautionary tale of how easily a nation could slip into anarchy in the tumultuous nineteenth century, even the so-called exceptional United States.