What are some events between the period of 1850 and 1861 that contributed to Southern secession from the Union?

Three very important events should be carefully looked at when
answering this question. The first is the Compromise of 1850. There were five parts to the
Compromise of 1850. First, California would be admitted to the Union as a free state. Next, two
new territories would be established, Utah and New Mexico, and slavery in those territories would
be determined by popular sovereignty, that is, the people of the territories would decide the
issue. The border of the state of Texas was determined, with Texas giving up some of its land in
exchange for $10 million. The slave trade, but not slavery itself, was ended in the District of
Columbia. Finally, a new, strict fugitive slave law was enacted. Each part of the compromise
upset one part of the country. California as a free state upset the south. Opening slavery to new
territories upset the north. Ending the slave trade in D.C. upset the south. Passing a new
fugitive slave law upset the north.

Another important event was the
Kansas Nebraska Act. In 1854, the Kansas Nebraska Act was passed. Two new territories, Kansas and
Nebraska, would be established in what was the Louisiana Purchase. These territories were north
of 36 degrees of latitude and according to the Missouri Compromise there would be no slavery
there. But the Kansas Nebraska Act stated that the issue of slavery in the new territories would
be decided by popular sovereignty, an idea borrowed from the Compromise of 1850, nullifying the
Missouri Compromise. This led to voter fraud in the Kansas territorial elections when pro-slavery
men from Missouri crossed into Kansas and illegally voted. This in turn led to violence as seen
in the attack on Lawrence and the massacre at Pottawatomie Creek led by John Brown. Many consider
the violence in Kansas as the true beginning of the Civil
War

Finally, a very important event that was not mentioned in the
previous post was the Dred Scott decision by the Supreme Court. This case was decided in 1857.
Dred Scott was a slave whose owner brought him into a free territory before returning him to a
slave state. Dred Scott sued in court claiming that he became free when he entered a free
territory. The Supreme Court said that African Americans were not citizens, that slaves were
property, and that when Congress banned slavery in the territories it was taking away property
without due process of law which is prohibited by the 5th Amendment. This meant Congress could
not ban slavery in U.S. territories thus opening vast amounts of the U.S. to slavery. This
outraged anti-slavery people throughout the U.S. increasing tensions that would lead to the Civil
War.