<P> As determined as Southern Republicans were to secure Missouri statehood with slavery, the three - fifths clause failed to provide the margin of victory in the 15th Congress . Blocked by Northern Republicans--largely on egalitarian grounds--with sectional support from Federalists, the bill would die in the upper house, where the federal ratio had no relevance . The "balance of power" between the sections, and the maintenance of Southern preeminence on matters related to slavery resided in the Senate . </P> <P> Northern voting majorities in the lower house did not translate into political dominance . The fulcrum for proslavery forces resided in the upper house of Congress . There, constitutional compromise in 1787 had provided for exactly two senators per state, regardless of its population: the South, with its small white demographic relative to the North, benefited from this arrangement . Since 1815, sectional parity in the Senate had been achieved through paired admissions, leaving the North and South, at the time of Missouri territory application for statehood, at eleven states each . </P> <P> The South, voting as a bloc on measures that challenged slaveholding interests and augmented by defections from Free State Senators with Southern sympathies, was able to tally majorities . The Senate stood as the bulwark and source of the Slave Power--a power that required admission of slave states to the Union to preserve its national primacy . </P> <P> Missouri statehood, with the Tallmadge amendment approved, would set a trajectory towards a Free State trans - Mississippi and a decline in Southern political authority . The question as to whether the Congress could lawfully restrain the growth of slavery in Missouri took on great importance among the slave states . The moral dimensions of the expansion of human bondage would be raised by Northern Republicans on constitutional grounds . </P>

Which territory was adjacent to the slave state of missouri