The most bitter guerrilla conflict in American history raged along the Kansas-Missouri border from 1856 to 1865, making that frontier the first battleground in the struggle over slavery. That fiercely contested boundary represented the most explosive political fault line in the United States, and its bitter divisions foreshadowed an entire nation torn asunder. Jeremy Neely now examines the significance of the border war on both sides of the Kansas-Missouri line and offers a comparative, cross-border analysis of its origins, meanings, and consequences. A narrative history of the border war and its impact on citizens of both states, The Border between Them recounts the exploits of John Brown, William Quantrill, and other notorious guerrillas, but it also uncovers the stories of everyday people who lived through that conflict. Examining the frontier period to the close of the nineteenth century, Neely frames the guerrilla conflict within the larger story of the developing West and squares that violent period with the more peaceful--though never tranquil--periods that preceded and followed it. Focusing on the countryside south of the big bend in the Missouri River, an area where there was no natural boundary separating the states, Neely examines three border counties in each state that together illustrate both sectional division and national reunion. He draws on the letters and diaries of ordinary citizens--as well as newspaper accounts, election results, and census data--to illuminate the complex strands that helped bind Kansas and Missouri together in post-Civil War America. He shows how people on both sides of the line were already linked by common racial attitudes, farming practices, and ambivalence toward railroad expansion; he then tells how emancipation, industrialization, and immigration eventually eroded wartime divisions and facilitated the reconciliation of old foes from each state. Today the "border war" survives in the form of interstate rivalries between collegiate Tigers and Jayhawks, allowing Neely to consider the limits of that reconciliation and the enduring power of identities forged in wartime. The Border between Them is a compelling account of the terrible first act of the American Civil War and its enduring legacy for the conflict's veterans, victims, and survivors, as well as subsequent generations.