Hence, while they had secured in 1819 the cession from Spain to the United States of the Slave-holding Floridas, and the organization of the Slave Territory of Florida in 1822--which subsequently came in as a Slave State under the same Act (1845) that admitted the Free State of Iowa--their greedy eyes were now cast upon the adjoining rich territories of Mexico. Efforts had (in 1827-1829) been made to purchase from Mexico the domain which was known as Texas. They had failed. But already a part of Texas had been settled by adventurous Americans under Mexican grants and otherwise; and General Sam Houston, an adherent of the Slave Power, having become a leading spirit among them, fomented a revolution. In March, 1836, Texas, under his guidance, proclaimed herself a Republic independent of Mexico. The War that ensued between Texas and Mexico ended in the flight of the Mexican Army and the capture of Santa Anna at San Jacinto, and a treaty recognizing Texan independence. In October, 1836, General Houston was inaugurated President of the Republic of Texas. Close upon this followed (in August, 1837) a proposition to our Government from the Texan envoy for the annexation of Texas to the United States. President Van Buren declined the offer. The Northern friends of Freedom were as much opposed to this annexation project as the advocates of Slavery were anxious for it. Even such conservative Northern Statesmen as Daniel Webster strongly opposed the project. In a speech delivered in New York [1837], after showing that the chief aim of our Government in the acquisition of the Territory of Louisiana was to gain command of the mouths of the great rivers to the sea, and that in the acquisition of the Floridas our policy was based on similar considerations, Mr. Webster declared that "no such necessity, no such policy, requires the annexation of Texas," and that we ought "for numerous and powerful reasons to be content with our present boundaries." He recognized that Slavery already existed under the guarantees of the Constitution and those guarantees must be fulfilled; that "Slavery, as it exists in the States, is beyond the power of Congress. It is a concern of the States themselves," but "when we come to speak of admitting new States, the subject assumes an entirely different aspect. Our rights and our duties are then both different. The Free States, and all the States, are then at liberty to accept or to reject;" and he added, "In my opinion the people of the United States will not consent to bring into the Union a new, vastly extensive and Slaveholding country, large enough for a half a dozen or a dozen States. In my opinion, they ought not to consent to it."