On May 30, 1854, the U.S. Congress passed the Kansas-Nebraska Act. This Act permitted people in the territories of Kansas and Nebraska to decide whether or not to allow slavery within their borders. The Act served to repeal the Missouri Compromise of 1820 which prohibited slavery north of latitude 36°30´.
The Kansas-Nebraska Act strongly angered those in the North as they considered the Missouri Compromise to be a binding agreement between them. However, in the South they strongly supported the Kansas-Nebraska Act, as expected since they were pro slavery. After the Kansas-Nebraska Act was passed, both those for and against slavery rushed in to settle Kansas to affect the outcome of the first election held there after the law went into effect. The election was conducted by pro slavery settlers and the election was dismissed when the anti slavery settlers charged them with holding a fraudulent election.
The anti slavery settlers decided to conduct another election but the pro slavery settlers refused to participate in it. The end result was an establishment of two opposing legislatures within the Kansas territory. This further led to violence erupting with the anti-slavery forces led by John Brown. As the number of deaths continued to rise, the territory was nicknamed “bleeding Kansas.” Federal troops were sent in by President Franklin Pierce so that they could support the pro-slavery settlers. They were also ordered to stop the violence and disperse the anti-slavery legislature.
Another election was called. Once again pro-slavery supporters won and once again they were charged with election fraud. The end result was that Congress would not recognize the constitution adopted by the pro-slavery settlers and Kansas was not allowed to become a state. Later, the number of anti-slavery settlers became much higher than that of the pro-slavery settlers and a new constitution was drawn up. On January 29, 1861, just before the start of the Civil War, Kansas was admitted to the Union as a free state.