Mining was one of the oldest uses to which slave-labor had been applied, and it still flourished in Siberia as the occupation of serfs and criminals. Mr. Webster, of course, was not ignorant of this very obvious fact; and that nature, therefore, instead of forbidding slave-labor in the Mexican conquests, opened to it a new and almost unlimited field in a region which is to-day one of the greatest mining countries in the world. Still less could he have failed to know that this form of employment for slaves was eagerly desired by the South; that the slave-holders fully recognized their opportunity, announced their intention of taking advantage of it, and were particularly indignant at the action of California because it had closed to them this inviting field. Mr. Clingman of North Carolina, on January 22, when engaged in threatening war in order to bring the North to terms, had said, in the House of Representatives: "But for the anti-slavery agitation our Southern slave-holders would have carried their negroes into the mines of California in such numbers that I have no doubt but that the majority there would have made it a slave-holding State."[1] At a later period Mr. Mason of Virginia declared, in the Senate, that he knew of no law of nature which excluded slavery from California. "On the contrary," he said, "if California had been organized with a territorial form of government only, the people of the Southern States would have gone there freely, and have taken their slaves there in great numbers. They would have done so because the value of the labor of that class would have been augmented to them many hundred fold."[2] These were the views of practical men and experienced slave-owners who represented the opinions of their constituents, and who believed that domestic slavery could be employed to advantage anywhere. Moreover, the Southern leaders openly avowed their opposition to securing any region to free labor exclusively, no matter what the ordinances of nature might be. In 1848, it must be remembered in this connection, Mr. Webster not only urged the limitation of slave area, and sustained the power of Congress to regulate this matter in the territories, but he did not resist the final embodiment of the principle of the Wilmot Proviso in the bill for the organization of Oregon, where the introduction of slavery was infinitely more unlikely than in New Mexico. Cotton, sugar, and rice were excluded, perhaps, by nature from the Mexican conquests, but slavery was not. It was worse than idle to allege that a law of nature forbade slaves in a country where mines gaped to receive them. The facts are all as plain as possible, and there is no escape from the conclusion that in opposing the Wilmot Proviso, in 1850, Mr. Webster abandoned his principles as to the extension of slavery. He practically stood forth as the champion of the Southern policy of letting the new territories alone, which could only result in