It made it much more difficult to create new slave-states.
It prohibited slavery North of a certain parallel, but only in the territories brought in under the Louisiana Purchase. When the new Mexican territories came in, they needed a new compromise. That one did not hold.
there was no slavery allowed
It allowed Slavery in the north.
Deal with slavery. They could not agree on how to change or end it, so they did nothing.
It declared that blacks were not citizens and could not have the rights of citizens. The Dred Scott decision also declared the Missouri Compromise of 1820, legislation which restricted slavery in certain territories, to be unconstitutional. This case was overturned by the 13th Amendment.
Deal with slavery. They could not agree on how to change or end it, so they did nothing.
Starting in the mid-1840s, decisions of the Supreme Court of Missouri became increasingly adverse to slaves bringing freedom suits. As we now know from the papers of the judges then serving, Judges William Barclay Napton and James Harvey Birch - who had been appointed to the court for life under the original constitutional scheme - were prepared to overrule the earlier cases and to hold that Missouri need not give comity to the law of the free territories. Napton and Birch seemed to be intending to end all freedom suits, to declare that Congress had no power to legislate on the subject of slavery in the territories, and to hold that the Missouri Compromise was unconstitutional.
compromise opens up for change that everyone obviously agrees is needed.
The arguments were the standards ones about the morals of slavery. These did not change much. It was the agreement they came to - the Missouri Compromise - that was notably successful because it was simple, a straightforward line in the sand, North of which slavery would be illegal. It kept the pece for thirty years.
How did William Henry Harrison's opinion of slavery change
As soon as Mexico became independent from Spain in 1821, it abolished slavery in most of its territories; however it wasn't explicitly stated in its constitution until 1833. This change in the constitution was one of the causes the Texian settlers started to conspire for the Texas independence -- most Texians were slave owners.
What kind of territories to create in the new lands. Should the status be created by Congress or should Popular Soverignty be permitted. How many states should be created and how to draw their borders.