What was the 1787 agreement that created a two-house U.S. Congress with proportional and equal representation?

The Connecticut Compromise created a two-house U.S. Congress with proportional representation in one chamber and equal state representation in the other.

The agreement, also called the Great Compromise, resolved a major dispute at the Constitutional Convention. Large states favored representation based on population, while small states wanted each state to have equal voting power. The compromise established the House of Representatives, where representation is based broadly on population, and the Senate, where every state has two senators.

Roger Sherman and Oliver Ellsworth of Connecticut are closely associated with the proposal. The arrangement helped keep both large and small states in the constitutional coalition, although it did not settle every disagreement at the convention.

The Connecticut Compromise is distinct from the Three-Fifths Compromise, which addressed how enslaved people would be counted for representation and taxation. It is also unrelated to the later Missouri Compromise and Compromise of 1850.