During the long interval coming between the two heroic ages of American history,--the age of Washington and Franklin, and the age of Lincoln and Grant,--it was but rarely that the nation gave its greatest gift to its best or its greatest son. Benton had come into the Senate at the same time that Missouri was admitted into the Union, with thanks, therefore, to the same measure, the Missouri Compromise bill. This shut out slavery from all territory north of the line of 36° 30', and did not make it obligatory even where it was permissible; and the immediate cause of Benton's downfall was his courage and persistency in defending the terms of this compromise from the attacks of the Southern slavery extensionists and disunionists. The pro-slavery feeling was running ever higher and higher throughout the South; and his stand on this question aroused the most furious anger among a constantly increasing number of his constituents, and made him the target for bitter and savage assaults on the part of his foes, the spirit of hostility against him being carried to such length as finally almost to involve him in an open brawl on the floor of the Senate with one of his colleagues, Foote, who, like his fellow fire-eaters, found that Benton was not a man who could be bullied. Indeed, his iron will and magnificent physique both fitted him admirably for such a contest against odds, and he seems to have entered into it with a positive zest. The political Abolitionists having put Polk in power, their action bore fruit after its kind, and very soon the question had to be faced, as to what should be done with the immense tracts of territory conquered from Mexico. Benton opposed, as being needless and harmful, the Wilmot Proviso, which forbade the introduction of slavery into any part of the territory so acquired. He argued, and produced in evidence the laws and Constitution of Mexico, that the soil of California and Mexico was already free, and that as slavery would certainly never be, and indeed could never be, introduced into either territory, the agitation of the question could only result in harm. Calhoun and the other extreme slavery leaders welcomed the discussion over this proviso, which led Benton to remark that the Abolitionists and the Nullifiers were necessary to each other,--the two blades of a pair of shears, neither of which could cut until they were joined together.