<Li> Battle of Osawatomie </Li> <Li> Marais des Cygnes massacre </Li> <P> Bleeding Kansas, Bloody Kansas or the Border War was a series of violent civil confrontations in the United States between 1854 and 1861 which emerged from a political and ideological debate over the legality of slavery in the proposed state of Kansas . The conflict was characterized by years of electoral fraud, raids, assaults, and retributive murders carried out by pro-slavery "Border Ruffians" and anti-slavery "Free - Staters" in Kansas and neighboring Missouri . </P> <P> At the heart of the conflict was the question of whether the Kansas Territory would allow or outlaw slavery, and thus enter the Union as a slave state or a free state . The Kansas--Nebraska Act of 1854 called for "popular sovereignty", requiring that the decision about slavery be made by the territory's settlers (rather than outsiders) and decided by a popular vote . Ongoing sectional tensions surrounding slavery quickly found focus in Kansas, with the pro-slavery element arguing that every settler had the right to bring his own property, including slaves, into the territory; anti-slavery "free soil" proponents argued not only that slavery was unethical, but that permitting slavery in Kansas would allow rich slaveholders to control the land to the exclusion of non-slaveholders . Missouri, a slave state since 1821, was populated by a large number of settlers with Southern sympathies and pro-slavery attitudes, many of whom tried to influence the decision in Kansas . The conflict was fought politically as well as between civilians, where it eventually degenerated into brutal gang violence and paramilitary guerrilla warfare . The term "Bleeding Kansas" was popularized by Horace Greeley's New York Tribune . </P>

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