The legislation known as the Missouri Compromise passed Congress in 1820. The bill that President James Monroe signed into law actually embodied several compromises painstakingly worked out and often hotly debated over a period of months between the congressional representatives of states where slavery was legal and those where it was not, and the most important of its provisions concerned slavery. The immediate issue was the Missouri Territory and its admission to the Union as a new state. Would it be admitted as a slave state, or should it be kept out of the Union unless it declared itself free? The larger question was how (if at all) slavery would be allowed to expand in the United States, or how it was to be restricted. Proslavery legislators would have preferred unlimited admittance of new slave states. Legislators from free states wanted no expansion of slavery; many wanted it abolished in the states where it already existed.