The U.S. South possessed an extensive history of looking outward, specifically southward, to solve internal tensions over slavery and economic competition from the 1820s through the 1860s. Nineteenth-century southerners invested in their futures, and in their identity as southerners, when they expanded their economic and proslavery connections to Latin America, seeking to establish a vast empire rooted in slavery that stretched southward to Brazil and westward to the Pacific Ocean. For these modern expansionists, failure to cement those connections meant nothing less than the death of the...