Why does the united states have bicameral congress

But a bicameral legislature provided the perfect opportunity for compromise—in fact, for "The Great Compromise." Small states got their equal representation in the Senate, large states got their proportional representation in the House, and everyone went home happy.
Bicameral Structure of Congress. The Constitution created a bicameral national legislature—that is, a Congress composed of two separate chambers, the Senate and the House of Representatives. ... Each state, no matter how large or small, has equal representation (two seats each) in the Senate.