The Great Compromise was forged in a heated dispute during the 1787 Constitutional Convention: States with larger populations wanted congressional representation based on population, while smaller states demanded equal representation. To keep the convention from dissolving into chaos, the founding fathers came up with the Great Compromise. The agreement, which created today’s system of congressional representation, now influences everything from “pork barrel” legislation to the way votes are counted in the electoral college during presidential elections.

The debate almost destroyed the U.S. Constitution.

At the Constitutional Convention of 1787, delegates from larger states believed each state’s representation in the newly proposed Senate should be proportionate to population.

Smaller states with lower populations argued that such an arrangement would lead to an unfair dominance of larger states in the new nation’s government, and each state should have equal representation, regardless of population.

The disagreement over representation threatened to derail the ratification of the U.S. Constitution since delegates from both sides of the dispute vowed to reject the document if they didn’t get their way. The solution came in the form of a compromise proposed by statesmen Roger Sherman and Oliver Ellsworth of Connecticut.

The Great Compromise created two legislative bodies in Congress.

Also known as the Sherman Compromise or the Connecticut Compromise, the deal combined proposals from the Virginia (large state) plan and the New Jersey (small state) plan.

According to the Great Compromise, there would be two national legislatures in a bicameral Congress. Members of the House of Representatives would be allocated according to each state’s population and elected by the people.

In the second body—the Senate—each state would have two representatives regardless of the state’s size, and state legislatures would choose Senators. (In 1913, the Seventeenth Amendment was passed, tweaking the Senate system so that Senators would be elected by the people.)

The plan was at first rejected but then approved by a slim margin on July 23, 1787.

George Washington presiding over the Constitutional Convention, 1787.  (Credit: Hulton Archive/Getty Images)
Hulton Archive/Getty Images
George Washington presiding over the Constitutional Convention, 1787. (Credit: Hulton Archive/Getty Images)

Smaller states have disproportionately more power in the Senate.

At the time of the convention, states’ populations varied, but not by nearly as much as they do today. As a result, one of the main lingering political effects of the Great Compromise is that states with smaller populations have a disproportionately bigger voice in the nation’s Congress.

As political scientist George Edwards III of Texas A&M University points out, California hosts about 68 times more people than Wyoming, yet they have the same number of votes in the Senate.

“The founders never imagined … the great differences in the population of states that exist today,” says Edwards. “If you happen to live in a low-population state you get a disproportionately bigger say in American government.”

The imbalance of proportionate power favoring smaller states in the Senate means that interests in those states, such as mining in West Virginia or hog farming in Iowa, are more likely to get attention—and money—from federal coffers.

“In the Senate when they’re trying to get to 51 votes to pass a bill, every vote counts,” says Todd Estes, a historian at Oakland University in Rochester, Michigan. “That’s when the smaller states can demand amendments and additions to bills to look out for their own state’s interest.”

The Great Compromise also skewed the electoral college.

The principle of protecting small states through equal representation in the Senate carries over into the electoral college, which elects the president, since the number of electoral votes designated to each state is based on a state’s combined number of representatives in the House and Senate.

That means, for example, even though Wyoming only has three votes in the electoral college, with the smallest population of all the states, each elector represents a far smaller group of people than each of the 55 electoral votes in the most populous state of California.

The system ensures power is distributed geographically.

Some scholars see the small-state bias in the Senate as critical. The arrangement means that power in the Senate is distributed geographically, if not by population, ensuring that interests across the entire country are represented.

Gary L. Gregg II, a political scientist at the University of Louisville in Kentucky, argues in a 2012 article in Politico that major metropolitan areas already hold power by hosting major media, donor, academic and government centers. The structure of the Senate and the corresponding representation in the electoral college, he says, ensures that the interests of rural and small-town America are preserved.

Was that the intention of the Founding Fathers? Edwards is doubtful since, as he points out, the majority of Americans at the time of Constitutional Congress came from rural areas—not urban. “No one was thinking about protecting rural interests,” Edwards says. “Rural interests were dominant at the time.”

Whatever the viewpoint on the fairness of the Great Compromise’s distribution of delegates to the Senate, it is unlikely to ever change. This is because equal-state representation in the Senate is specifically protected in the Constitution.

According to Article V of the Constitution, no state can lose its equal representation in the Senate without the state’s permission. And no state is likely to willingly give up their say in the Senate.