Its safety naturally, therefore, became among the slave class an object of prime importance.  Southern jealousy in this regard ultimated inevitably in Southern narrowness, Southern sectionalism, which early manifested themselves in the exclusion from lead in national affairs of Northern public men, reputed to be unfriendly to slavery.  Webster as late as 1830, protested warmly against this intolerance.  Like begets like.  And the proscribing of anti-slavery politicians by the South, created in turn not a little sectional feeling at the North, and helped to stimulate there a consciousness of sectional differences, of antagonism of interests between the two halves of the Union.

Discontent with the original basis of the Union, which had given the South its political coign of vantage, broke out first in New England.  The occasion, though not the cause, of this discontent was, perhaps, the downfall of the Federal party, whose stronghold was in the East.  The commercial and industrial crisis brought on by the embargo, and which beggared, on the authority of Webster, “thousands of families and hundreds of thousands of individuals” fanned this Eastern dissatisfaction into almost open disaffection towards a government dominated by Southern influence, and directed by Southern statesmanship.  To the preponderance of this Southern element in national legislation New England traced her misfortunes.  She was opposed to the War of 1812, but was overruled to her hurt by the South.  In these circumstances New England went for correcting the inequalities of the original basis of the Union, which gave to the South its undue preponderance in shaping national laws and policies.  This was the purpose of the Hartford Convention, which proposed the abrogation of the slave representation clause of the Constitution, and the imposition of a check upon the admission of new States into the Union.  The second proposition did not say “new slave States,” but new slave States was, nevertheless, intended by the Convention.  Here in point of time and magnitude, was the first distinct collision of the two sets of ideas and interests of the Republic.

Following the Treaty of Ghent other and imperious questions engaged the public attention—­questions of the tariff, of finance, internal improvements, national defence, a new navy, forts and fortifications.  Hard times, too, engrossed an enormous share of this attention.  The immediate needs and problems of the hour pushed into the background all less pressing ones.  The slavery question amidst the clamor and babel of emergent and material interests, lost something of its sectional heat and character.  But its fires were not extinguished, only banked as events were speedily to reveal.

The application of Missouri for admission into the Union as a slave State four years after the Hartford Convention blew to a blaze the covered embers of strife between the sections.  The North was violently agitated.  For the admission of a new slave State meant two more slave votes in the Senate, and an increase on the old inequitable basis of slave representation in the lower House of Congress.  It meant to the Northern section indefinite Southern ascendency, prolonged Southern lead in national legislation.  All the smouldering passions of the earlier period, of embargo, and non-intercourse, and the war of 1812, flamed suddenly and fiercely in the heart of the free States.