<Li> Violence by pro-slavery looters from Missouri known as Border Ruffians and anti-slavery groups known as Jayhawkers breaks out in "Bleeding Kansas" as pro-slavery and anti-slavery supporters try to organize the territory as slave or free . Many Ruffians vote illegally in Kansas . Estimates will show that the violence in Kansas resulted in about 200 persons killed and $2 million worth of property destroyed during the middle and late 1850s . Over 95 percent of the pro-slavery votes in the election of a Kansas territorial legislature in 1855 were later determined to be fraudulent . </Li> <Li> Anti-slavery Kansans draft an anti-slavery constitution, the Topeka Constitution, and elect a new legislature, which actually represent the majority of legal voters . Meanwhile, the initial fraudulently elected but legal Kansas legislature still exists . </Li> <Tr> <Td> 1856 </Td> <Td> <Ul> <Li> May 21: Missouri Ruffians and local pro-slavery men sack and burn the anti-slavery town of Lawrence, Kansas . </Li> <Li> John Brown, an abolitionist born in Connecticut, and his sons kill five pro-slavery men from Pottawatomie Creek in retaliation for the Sacking of Lawrence . </Li> <Li> May 22: Congressman Preston Brooks of South Carolina beats with a cane and incapacitates Senator Charles Sumner of Massachusetts on the floor of the U.S. Senate . In a speech in the Senate chamber, The Crime Against Kansas, Sumner ridicules slaveowners--especially Brooks's cousin, U.S. Senator Andrew Butler of South Carolina--as in love with a prostitute (slavery) and raping the virgin Kansas . Brooks is a hero in the South, Sumner a martyr in the North . </Li> <Li> In the 1856 U.S. presidential election Republican John C. Frémont crusades against slavery . The Republican slogan is "Free speech, free press, free soil, free men, Frémont and victory!" Democrats counter that Fremont's election could lead to civil war . The Democratic Party candidate, James Buchanan, who carries five northern and western states and all the southern states except Maryland, wins . </Li> <Li> Thomas Prentice Kettell, a New York Democrat, writes Southern Wealth and Northern Profits, a lengthy statistical pamphlet about the economies of the Northern and Southern regions of the country . The book receives wide acclaim among secessionists in the South and much derision from anti-slavery politicians in the North, even though some historians think Kettell intended it as an argument that the two regions are economically dependent upon each other . </Li> <Li> Filibusterer William Walker, in alliance with local rebels, overthrows the government of Nicaragua and proclaims himself president . He decrees the reintroduction of slavery . Many of Walker's men succumb to cholera and he and his remaining men have to be rescued by the U.S. Navy in May 1857 . </Li> </Ul> </Td> </Tr> <Ul> <Li> May 21: Missouri Ruffians and local pro-slavery men sack and burn the anti-slavery town of Lawrence, Kansas . </Li> <Li> John Brown, an abolitionist born in Connecticut, and his sons kill five pro-slavery men from Pottawatomie Creek in retaliation for the Sacking of Lawrence . </Li> <Li> May 22: Congressman Preston Brooks of South Carolina beats with a cane and incapacitates Senator Charles Sumner of Massachusetts on the floor of the U.S. Senate . In a speech in the Senate chamber, The Crime Against Kansas, Sumner ridicules slaveowners--especially Brooks's cousin, U.S. Senator Andrew Butler of South Carolina--as in love with a prostitute (slavery) and raping the virgin Kansas . Brooks is a hero in the South, Sumner a martyr in the North . </Li> <Li> In the 1856 U.S. presidential election Republican John C. Frémont crusades against slavery . The Republican slogan is "Free speech, free press, free soil, free men, Frémont and victory!" Democrats counter that Fremont's election could lead to civil war . The Democratic Party candidate, James Buchanan, who carries five northern and western states and all the southern states except Maryland, wins . </Li> <Li> Thomas Prentice Kettell, a New York Democrat, writes Southern Wealth and Northern Profits, a lengthy statistical pamphlet about the economies of the Northern and Southern regions of the country . The book receives wide acclaim among secessionists in the South and much derision from anti-slavery politicians in the North, even though some historians think Kettell intended it as an argument that the two regions are economically dependent upon each other . </Li> <Li> Filibusterer William Walker, in alliance with local rebels, overthrows the government of Nicaragua and proclaims himself president . He decrees the reintroduction of slavery . Many of Walker's men succumb to cholera and he and his remaining men have to be rescued by the U.S. Navy in May 1857 . </Li> </Ul>

Who became the voice of the abolitionist movement in the years leading up to the civil war