Why did Henry clay propose the Missouri compromise to resolve the issue of missuori state hood?

The Missouri Compromise of 1820 was the work of Congressman Henry Clay of Kentucky. By 1820 there were already 10,000 or more slaves in the territory that was to become Missouri and a slave state at that. There was a pressing need to keep the number of slave and free states in balance. In order to appease both the North and the South, Clay proposed to congress a plan to keep things in balance. Missouri could enter as a slave state and part of Massachusetts would be divided to make a new Northern free state called Maine. The compromise worked and the heated debates over slavery, for the time being was put to rest. But it was not a permanent solution in that the US continued to grow.