Notwithstanding the fact that Colonel Davis' right foot had been shattered early in the morning, he had refused to leave the field for aid, but now at the close of the action he fell fainting from his horse. The wound was a dangerous one, and as the surgeons were of the opinion that more than a year must elapse before he could hope to walk, as soon as he was able to travel, General Taylor insisted on his going home, and thus closed his career in the Mexican War. VII. Enters the Senate This exploit at Buena Vista created the profoundest enthusiasm throughout the country, and the Legislatures of several states passed resolutions thanking him for his services. Governor Brown of his own state, in obedience to an overwhelming popular sentiment, a few weeks after his return, appointed Colonel Davis to fill a vacancy that had occurred in the Senate--an appointment which was speedily ratified by the Legislature. When, in 1847, Mr. Davis took his seat in the Senate, that irrepressible conflict, inevitable from the hour that the Constitutional Convention of 1787 sanctioned slavery as an institution within the United States, had reached a crisis which was threatening the very existence of the Union. The Missouri Compromise prohibiting slavery north of 36° 30' had failed to sanction it in express terms south of that parallel, and while in 1820 probably no one would have denied that this was the logical and obvious meaning of that measure, such was not the case thirty years later. The Abolitionists had opposed the annexation of Texas, believing, as Mr. Adams declared, that such an event would justify the dissolution of the Union. In finally accepting Texas with bad grace, they served notice that it was their last concession. Therefore when the application of the Missouri Compromise to the vast territory acquired from Mexico would have given over a large portion of it to slavery, they brought forward the Wilmot Proviso, a measure, the effect of which was to abrogate the Missouri Compromise in so far as it affected slavery south of that line, while leaving its prohibition as to the north side in full force. [Illustration: Jefferson Davis as United States Senator in 1847] Mr. Davis participated in the discussion of these questions and at once became the ablest and most consistent of those statesmen who, contending for the strict construction of the Constitution and the broadest principles of state sovereignty, sought to prevent Congress from violating the one by infringing on the prerogatives of the other. Holding that the Constitution sanctioned slavery, that Congress had specified its limits, that the territories belonged in common to the states, he contended that the South could not accept with honor anything less than that the Missouri Compromise extended to the Pacific Ocean.