The double rule of apportionment fashioned at the 1787 Constitutional Convention served as the formal basis for the division of political representation within the U.S. Congress and the Electoral College for the next seventy-four years. The rule divided national representation among the states in three distinct ways: proportionally according to population in the U.S. House of Representatives, equally in the U.S. Senate, and the combined effect of these two methods in the Electoral College. The unique and combined distributional logics of these terms of apportionment sustained and oriented much of the constitutional development of the American political order until its collapse into civil war in 1861.

Given the deep sectional divisions that animated the 1787 Convention's debate over representation, the new rule of apportionment initially inspired different expectations and anxieties concerning each section's future political strength within the national government. Southern statesmen recognized that the new rule's demographic calculus likely guaranteed northern state majorities in the House and the Electoral College until at least the 1800 Census. Many were convinced however that the new apportionment rule was particularly well designed for the South's rapidly growing population. The seemingly effortless development of the southwestern territory (and future states) of Kentucky and Tennessee throughout the 1780s provided reassuring evidence of the section's future strength in the Senate as well.

Northern statesmen were decidedly less confident about the longerterm consequences of the new rule of apportionment.