The Missouri Controversy was the dispute over the terms by which the area of Missouri, which had been carved out by the Louisiana Purchase, would be let into the union as a state. The dispute was over the number of slaves already residing in the area, a number exceeding 10,000. James Tallmadge, a Republican Congressman from New York, argued that the introduction of more slaves should be banned and that children of slaves already in Missouri should be freed at the age of twenty-five. The proposal by Tallmadge sparked over two years of controversy that shattered Republican unity. His restriction passed in the house, but it did not pass in the senate. When congress reconvened in 1820 Senator Jesse Thomas of Illinois proposed a three-part compromise.