Summary: Slave Dred Scott fought for his freedom... In court! He argued that since his owner had brought him to a free state, since he was a citizen, he was rightful to be free. This case eventually ended up in the Supreme Court, where they said Scott would remain a slave, as he was property of his owner, and his owner could not be deprived of his property, and so forth, Scott was not a citizen. Also, they ruled the Missouri Compromise unconstitutional as it went against the 5th Amendment.
Northern Perspective: The North was angry that slaves were seen as property and not citizens, and were a little upset that the Missouri Compromise was unconstitutional, meaning that they would no longer have more free states, than the South's slave states.
Southern Perspective: Overall, the South was happy, with the Missouri Compromise being ruled unconstitutional, and with the fact that slaves were property and not citizens being reintroduced.