The Missouri Compromise, also called the Compromise of 1820, was a plan proposed by Henry Clay of the U.S. state of Kentucky. It was signed by President James Monroe and passed in 1820. The agreement was between the pro-slavery and anti-slavery groups in the United States Congress, mostly about the regulation of slavery in the western territories. It admitted Missouri as a slave state to please the South and it also admitted Maine as a free state to please the North. It kept the balance of power in the United States Senate between the free states and slave states. The plan also called for slavery to be banned from the Louisiana Territory north of the parallel 36 degrees 30' north (also known as the Missouri Compromise Line), except inside the borders of the proposed state of Missouri.