If the weight of reason had not already been on the side of admitting Louisiana, the necessities of war would have enforced it. Six years after Louisiana entered the Union, Missouri applied for admission as a slave State. A violent agitation at once arose, continued for two years, and was finally allayed by the famous compromise of 1820. The outbreak was so sudden, its course so turbulent, and its subsidence so complete, that for many years it was regarded as phenomenal in our politics, and its repetition in the highest degree improbable if not impossible. The "Missouri question," as it was popularly termed, formally appeared in Congress in the month of December, 1818; though during the preceding session petitions for a State government had been received from the inhabitants of that territory. When the bill proposing to admit the State came before the House, Mr. James Tallmadege, jun., of New York, moved to amend it by providing that "the further introduction of slavery be prohibited in said State of Missouri, and that all children born in that State after its admission to the Union shall be free at the age of twenty-five years." The discussion which followed was able, excited, and even acrimonious. Mr. Clay took an active part against the amendment, but his great influence was unavailing in the face of the strong anti-slavery sentiment which was so suddenly developed in the North. Both branches of Mr. Tallmadge's amendment were adopted and the bill was passed. In the Senate the anti-slavery amendment encountered a furious opposition and was rejected by a large majority. The House refused to recede; and, amid great excitement in the country and no little temper in Congress, each branch voted to adhere to its position. Thus for the time Missouri was kept out of the Union.