Northern members of Congress; and thus began the first great slavery agitation in the nation.  This controversy lasted several months, and became very angry and exciting—­the House of Representatives voting steadily for the prohibition of slavery in Missouri, and the Senate voting as steadily against it.  Threats of the breaking up of the Union were freely made, and the ablest public men of the day became seriously alarmed.  At length a compromise was made, in which, as in all compromises, both sides yielded something.  It was a law, passed on the 6th of March, 1820, providing that Missouri might come into the Union with slavery, but that in all the remaining part of the territory purchased of France which lies north of thirty-six degrees and thirty minutes north latitude, slavery should never be permitted.  This provision of law is the “Missouri Compromise.”  In excluding slavery north of the line, the same language is employed as in the Ordinance of 1787.  It directly applied to Iowa, Minnesota, and to the present bone of contention, Kansas and Nebraska.  Whether there should or should not be slavery south of that line, nothing was said in the law.  But Arkansas constituted the principal remaining part south of the line; and it has since been admitted as a slave State, without serious controversy.  More recently, Iowa, north of the line, came in as a free State without controversy.  Still later, Minnesota, north of the line, had a territorial organization without controversy.  Texas, principally south of the line, and west of Arkansas, though originally within the purchase from France, had, in 1819, been traded off to Spain in our treaty for the acquisition of Florida.  It had thus become a part of Mexico.  Mexico revolutionized and became independent of Spain.  American citizens began settling rapidly with their slaves in the southern part of Texas.  Soon they revolutionized against Mexico, and established an independent government of their own, adopting a constitution with slavery, strongly resembling the constitutions of our slave States.  By still another rapid move, Texas, claiming a boundary much farther west than when we parted with her in 1819, was brought back to the United States, and admitted into the Union as a slave State.  Then there was little or no settlement in the northern part of Texas, a considerable portion of which lay north of the Missouri line; and in the resolutions admitting her into the Union, the Missouri restriction was expressly extended westward across her territory.  This was in 1845, only nine years ago.

Thus originated the Missouri Compromise; and thus has it been respected down to 1845.  And even four years later, in 1849, our distinguished Senator, in a public address, held the following language in relation to it: