Why every state has two senators: it all goes back to a compromise struck at the Constitutional Convention of 1787.

In the summer of 1787, the 55 delegates to the Constitutional Convention in Philadelphia were at an impasse. They'd come together from 12 of the nation's 13 states * to write a federal Constitution--something to replace the Articles of Confederation, which had proven too weak.

But by late June, the effort neared collapse over a fundamental disagreement. Delegates from large states and small states were at odds over how to allocate representatives in a new national legislature: distribute them according to population or give each state an equal vote?

Two competing plans were proposed for structuring the U.S. Congress. In the end, the Great Compromise broke the stalemate and created the House and Senate we know today.

VIRGINIA PLAN

A two-chamber national legislature; representatives in both houses would be apportioned based on population

Supported By:

James Madison of Virginia (who authored the plan), James Wilson of Pennsylvania, Gouverneur Morris of Pennsylvania, and Alexander Hamilton of New York

NEW JERSEY PLAN

A single-body national legislature, in which each state would have one vote-very similar to the national structure already in place under the...