Missouri Compromise

              In the year of 1820, Missouri wanted to become a slave state of the union. At the time, there was a very delicate balance of senate members in congress between slave and free states. This equality was wanted because if one side gained majority, it could decide the pressing situation of slavery for the whole nation. Northerners didn't want Missouri to be let into the union as a state because it would upset the balance. Southerners, on the other hand, wanted to gain majority in congress with a new slave state's help, Missouri. In the end, a compromise was reached. Missouri would be admitted a slave state, but Massachusetts would be split apart and a new free state would form, Maine. They also decided the 36 30 line rule. It meant that all future states above the line had to be free, and below were to be slave. 

http://www.waymarking.com/waymarks/WM812H_Missouri_Compromise_36_30_Enid_Oklahoma