But little explanation of these events is necessary. In December, 1817, Mississippi was admitted into the Union, and Alabama became a territory. On March 2, 1819, Arkansas was organized into a territory, and on December 14, Alabama was admitted to the Union. In this year commenced the earnest and acrimonious discussion between the North and South in regard to the extension of slavery. Both Maine and Missouri sought admission as States. Maine was admitted, March 15th, 1820, and, after a two years' wild debate, it was thought the whole question of slavery was settled by the Missouri Compromise, February 27, 1821. This compromise was the adoption of a provision in the bill for the admission of Missouri, that in all territory south of thirty-six degrees and thirty minutes north latitude (the southern boundary of the State of Missouri) slavery might exist; but it was prohibited in the region north of that line. A member of congress from Georgia prophetically said in the course of the debate: "A fire has been kindled, which all the waters of the ocean cannot put out, and which only seas of blood can extinguish." Had the Missouri Compromise been kept inviolate to the present day, slavery might still have existed below thirty-six degrees and thirty minutes north latitude. The commerce of the United States was greatly injured by swarms of privateers under Spanish-American flags, who had degenerated into pirates, and so became outlaws, subject to chastisement by any nation. They infested the West Indian seas and the northern coast of South America. Against these pirates and to protect American commerce, the United States sent Commodore Perry, with two ships of war, in the spring of 1819. Perry died of yellow fever soon after his arrival in southern waters. In June, 1822, Captain Allen, of the United States schooner _Alligator_, successfully fought a band of pirates in the West Indies, captured one of their schooners, and recaptured five American vessels; but Captain Allen was subsequently killed in an encounter with the bold buccaneers. The next year Commodore Porter, with a larger force, entered the pirate infested waters and almost completely destroyed the buccaneers. It was the policy of the government of the United States to favor the revolt of the Spanish-American provinces, whose flag these pirates had dishonored, as a means for preventing the establishment, in the future, of monarchical powers on the American continent. The latter policy was avowed by the president, and has never been lost sight of by our government, and is known in history as the "Monroe Doctrine." Accordingly, on the recommendation of the president, congress, early in 1822, resolved by a unanimous vote to recognize the independence of five of the revolted colonies, and appropriated $100,000 to defray the expenses of envoys to the seat of government of each, whom the president soon afterward appointed.