To compose the boundary troubles with Spain, a treaty was negotiated in 1819, which, with many gains, entailed some signal losses upon the United States. The whole of Florida was ceded by Spain, an acquisition which proved of great value to us in every point of view. As Florida had become separated from the other Spanish colonies by the cession of Louisiana, the government at Madrid found difficulty in satisfactorily administering its affairs and guarding its safety. South of the United States, to the Straits of Magellan, the Spanish flag floated over every foot of the continent except the Empire of Brazil and some small colonies in Guiana. The cession of Louisiana to Bonaparte involved the loss of Florida which was now formally transferred to the United States. But Spain received more than an equivalent. The whole of Texas was fairly included in the Louisiana purchase,--if the well-studied opinion of such eminent statesmen as Clay, John Quincy Adams, Van Buren, and Benton may be accepted,--and we paid dearly for Florida by agreeing to retreat from the Rio Grande to the Sabine as our south-western frontier, thus surrendering Texas to Mexico. The western boundary of the Louisiana territory was defined as beginning at the mouth of the Sabine (which is the boundary of the State of Louisiana to-day), continuing along its western bank to the 32° of north latitude, thence by a line due north to the Red River, thence up the Red River to the 100th meridian west from Greenwich, or the 23d west from Washington, thence due north to the Arkansas, thence following the Arkansas to its source in latitude 42°, and thence by that parallel to the Pacific Ocean. Should the Arkansas fall short of the 42°, a due north line to that parallel was to be taken. The United States solemnly renounced all claim to territories west or south of the line just mentioned, and Spain renounced all claim to territory east or north of it. Thus all boundary disputes with Spain were ended, and peace was secured, though at a great cost; as events in after years so fully proved.