Uncovers how Mexican-American and Cuban-American writings during the US Civil War shaped Latinidad amid conflicts over race, slavery, and national identity The mid-nineteenth century was a crucible for the emergence of US Latinidad. Against the backdrop of the US-Mexico War, the Cuban wars of independence, and the American Civil War, Latinx identity took shape in fractured and contested ways--through struggles over race, slavery, and governance in the United States, Mexico, and Cuba. Latinx Civil Wars uncovers this turbulent history through a rich archive of letters, military dispatches, journalism, and literature that reveal Latinx identity as itself at war during the long Civil War era. These embattled writings illuminate how questions of race, displacement, and assimilation reverberated across national and cultural borders, producing competing visions of what it meant to be Latinx in nineteenth-century America. Alemán reconstructs this contested landscape by bringing together well-known figures--such as María Amparo Ruiz de Burton, Loreta Janeta Velázquez, and Rafael Chacón--with overlooked participants like Miguel Otero, James Santiago Tafolla, and Federico and Adolfo Cavada. Their lives and words trace a diaspora negotiating the fraught intersections of race, class, language, and national allegiance across Union and Confederate lines. Challenging historians and literary scholars alike, Latinx Civil Wars demonstrates how the formation of Latinx identity was entangled with slavery, independence, racialization, and rebellion--revealing Latinidad as a product not of unity, but of conflict and contradiction.