States Rights and Federal Rights
States wanted to be able to choose if they were going to be a slave state or a free state. South wanted state rights so they could choose to have slaves for their plantations. North wanted there to be federal rights because they believed in a union and this would benefit their businesses. The south wanted state rights because they wanted to choose if they were going to be a slave or a free state. The north wanted to have federal rights because they thought there shouldn't be a choice. That is a reason why they fought.
Daniel Webster
Representative of New Hampshire and Senator of Massachusetts. He believed in Federal Power. He thought that the states should support the government. Webster said that this is one nation and we should act like it. The south believed they should choose if they were a slave state or not, but Webster said it wouldn't be a nation without The Federal Government.
John C. Calhoun
He wanted there to be state rights. He said that if we didn't allow a state to choose if they wanted to be a free or slave state then rebellion would occur. John said that this would ruin our union and people will fight.
Event
The Missouri Compromise created a line that said above is free and below is slave. Many people did not agree with this so they created the Kansas-Nebraska Act. This canceled out the Missouri Compromise and it said that states could choose if they were a slave state or not.