What agreement created proportional representation in the House and equal state representation in the Senate?

The Connecticut Compromise created proportional representation in the House and equal state representation in the Senate.

Also called the Great Compromise or Sherman Compromise, the agreement was reached during the Constitutional Convention of 1787. Large states favored the Virginia Plan, which would have based legislative representation largely on population. Small states supported the New Jersey Plan, which would have preserved equal state voting in a single-chamber legislature.

The compromise established a bicameral Congress. Representation in the House of Representatives would be based on population, while every state would receive two senators, regardless of population. This structure balanced competing ideas of popular representation and state equality.

Roger Sherman of Connecticut played a major role in advancing the arrangement, which is why the agreement is commonly associated with Connecticut. It helped break a deadlock that threatened the convention’s work. The compromise did not settle every representation dispute: the convention separately adopted the Three-Fifths Compromise concerning how enslaved people would be counted for apportionment and taxation.