Therefore, when in 1818 the territory of Missouri applied for admission to the Union as a State, the South was greatly excited by the proposition from Mr. Tallmadge, of New York, that its admission should be conditioned upon the prohibition of slavery within its limits. It was a revelation to the people of the North that so bitter a feeling should be aroused by opposition to the extension of an acknowledged evil, which had been abolished in all their own States. The Southern leaders, on their side, maintained that Congress could not, under the Constitution, legislate on such a subject,--that it was a matter for the States alone to decide; and that slavery was essential to the prosperity of the Southern States, as white men could not labor in the cotton and rice fields. The Northern orators maintained that not only had the right of Congress to exclude slavery from the Territories been generally admitted, but that it was a demoralizing institution and more injurious to the whites even than to the blacks. The Southern leaders became furiously agitated, and threatened to secede from the Union rather than submit to Northern dictation; while at the North the State legislatures demanded the exclusion of slaves from Missouri. Carl Schurz, in his admirable life of Clay, makes a pertinent summary: "The slaveholders watched with apprehension the steady growth of the Free States in population, wealth, and power.... As the slaveholders had no longer the ultimate extinction, but now the perpetuation, of slavery in view, the question of sectional power became one of first importance to them, and with it the necessity of having more slave States for the purpose of maintaining the political equilibrium, at least in the Senate. A struggle for more slave States was to them a struggle for life." Thus the two elements of commercial profit and political power were involved in the struggle of the South for the maintenance and extension of slavery. The House of Representatives in 1819 adopted the Missouri bill with the amendment restricting slavery, but the Senate did not concur; and Alabama was admitted as a Territory without slavery restriction. In the next Congress Missouri was again introduced, but the antislavery amendment was voted down. In 1820 Mr. Thomas, a senator from Illinois, proposed, as a mutual concession, that Missouri should be admitted without restriction, but that in all that part of the territory outside that State ceded by France to the United States, north of the latitude of 36° 30' (the southern boundary of Missouri), slaves should thereafter be excluded; and this bill was finally passed March 2,1820. Mr. Clay is credited with being the father of this compromise, but, according to Mr. Schurz, he did not deserve the honor. He adopted it, however, and advocated it with so much eloquence and power that it owed its success largely to his efforts, and therefore it is still generally ascribed to him.