What did the Great Compromise solve?

The Great Compromise solved the deadlock between large and small states over how the new national legislature would be apportioned, allowing the Constitutional Convention to move past its most threatening crisis and finish drafting the Constitution. The dispute had two dimensions. The first was demographic. Virginia in 1787 had nearly 750,000 people, the largest state by far, while Delaware had only about 60,000. Under the Virginia Plan's proportional formula, Virginia, Pennsylvania, and Massachusetts together would have controlled close to half of both chambers and could outvote the smallest states on every issue. Small state delegates feared their interests in commerce, fishing rights, taxation, and especially access to western lands would be permanently subordinated. William Paterson of New Jersey told the convention on June 15, 1787 that he would rather submit to a monarch than to a fate that swallowed up his state.

The second dimension was conceptual. Should the new union be a confederation of equal sovereign states, as the Articles had treated it, or a national government deriving authority directly from the people? Madison and James Wilson of Pennsylvania argued for a national government in which population was the only fair basis. Roger Sherman and Oliver Ellsworth of Connecticut argued that states had created the union and should be represented as states. By preserving equal state representation in the Senate while giving population its weight in the House, the compromise let both views coexist and fitted the structure to a federal system that was partly national and partly confederal.

The compromise also resolved several practical disputes. It guaranteed that revenue bills must originate in the population based House, satisfying the principle that taxation should reflect population. It gave the Senate the role of long term deliberation and check on hasty legislation, with six year terms and staggered elections. It set the stage for the Three-Fifths Compromise of July 12, 1787 by establishing that representation in the House would depend on population, then defining how to count enslaved persons. It established the formula that produced the Electoral College, which combines House numbers and two Senate slots per state to allocate electors.

Without the compromise the convention would almost certainly have broken up in failure during early July 1787. Small state delegates had begun to threaten withdrawal, and large state delegates were unwilling to concede ground. The compromise saved the convention and the Constitution, and the structural balance it created has held since the first Congress met in 1789.