Quoting frequently from Forbes, Kytle emphasizes "that the story of American democracy cannot be told apart from the story of America slavery." Kytle discusses two key results of the Missouri Compromise of 1820, which admitted Missouri as a slave state, Maine as a free state and banned slavery north of the 36°
30'parallel line. One risk that antislavery advocates worried about was the Compromise "'evasion' would lead inevitably to the conclusion that 'a free black is not a citizen' (p. 119)."
The latter response was prescient. For, as Forbes argues, the Missouri controversy had two critical legacies. One legacy was that the second compromise contained the seeds of destruction for the key antislavery measure - the 36°30' prohibition line - in the first. By providing a precedent for depriving blacks of citizenship rights, Clay's ambiguously worded bill laid the foundation for the 1857 Dred Scott v. Sanford decision. That decision, in turn, ruled that the 36° 30' prohibition line was unconstitutional.The latter is another reminder of how the slavery issue mixed into partisan and intra-party conflicts in ways that seem bizarre, especially from today's perspective.
The second legacy of the Missouri Compromise was convincing many Americans that slavery posed the gravest of dangers to the republic. And, in the decade following the Missouri Compromise, most American politicians took this lesson to heart, studiously avoiding the divisive issue. Thinking the slavery question too explosive, if not completely settled, northerners and southerners found themselves drawn into intersectional coalitions that tend to shock later observers. The People's Party of New York, which was led by James Tallmadge [the Congressman who set off the Missouri crisis by proposing to ban slavery there], for example, backed proslavery leader John C. Calhoun, while Georgian William Crawford received the endorsement of abolitionist William Lloyd Garrison.