The intense, generational animosity between the University of Kansas and the University of Missouri—known historically as the "Border War"—is rooted in a deep, violent history originating from the Antebellum era and the American Civil War. During the "Bleeding Kansas" period, pro-slavery militias from Missouri frequently crossed the border to attack abolitionist settlements in Kansas, including the infamous burning of Lawrence, Kansas. This century-old political and cultural conflict transitioned into the collegiate sporting arena, where the two flagship universities developed a fierce, deeply bitter rivalry defined by regional pride, historical memory, and decades of high-stakes competition across every shared athletic event.