The United States Senate is the upper house of the legislative branch of the federal government, with the House of Representatives referred to as the lower house. In the United States, the terms “upper” and “lower” house are not literal; they date back to a time in the 1780s when the Senate and House of Representatives met on the upper and lower floors of Federal Hall, their base in the former U.S. capital of New York City. 

While some so-called bicameral (“two chambers” in Latin) legislatures around the world feature two separate bodies with distinct levels of power—such as the House of Lords and the House of Commons in the U.K. Parliament—the Senate and House of Representatives actually have roughly the same amount of power in the U.S. government.

In fact, both houses of Congress must approve identical pieces of legislation—known as bills—in order for them to become law. Since the early 1800s, both chambers of the U.S. Congress have been based in the Capitol building in Washington, D.C.

The Founding Fathers and the Senate

Although the U.S. Senate in its present form dates back to 1789, the year Congress as it is currently constructed met for the first time, it was not part of the original unicameral (“one chamber”) legislature established by the Founding Fathers.

Initially, the Founding Fathers, or “framers” of the U.S. Constitution, drafted a document called the Articles of Confederation, which was written in 1777 and ratified in 1781 by the Continental Congress (a temporary legislative body with representatives from each of the 13 colonies, which became the original 13 states).

The Articles established a unicameral Congress and the Supreme Court, but no Office of the President. Indeed, the first Congress had wide-ranging powers that included the authority to declare war and sign and negotiate treaties. Other government functions, such as taxation and the collection thereof, were left to the states.

This original Congress was made up of members elected by each of the states, which were represented equally. However, it soon became clear that this form of government was inadequate in many ways—namely, the more-populated states complained that they should have greater representation in the government than their smaller counterparts and that the unicameral legislature did not provide adequate checks and balances against potential abuse of power.

The Difference Between Congress and The Senate

With the writing of the U.S. Constitution, which was ratified in 1787, the framers effectively went back to the drawing board and created a bicameral legislature.

It was modeled after similar forms of government in Europe that dated back to the Middle Ages. Notably, from their perspective, England had a bicameral Parliament as fact back as the 17th century.

The Constitution established the two houses of Congress, with the Senate featuring two members from each state, appointed to six-year terms, and the House of Representatives made up of varying members from each state, based on population, elected to two-year terms.

Importantly, the Constitution originally stipulated that while members of the House of Representatives were elected by the citizens of each state (meaning: those eligible to vote), members of the Senate were instead appointed by the individual legislatures of the 13 states.

This was the case until 1913, with the passage of the 17th Amendment to the Constitution, which effectively changed the process to what it still is today, with Senators elected to six-year terms by the citizens of their respective states.

What Does a Senator Do?

Originally, the framers intended to have the House be focused on more pressing, everyday concerns, while the Senate would be the more deliberative, policy-centric body. However, these distinctions have generally blurred over the decades since, and now the two houses hold the same amount of power, and essentially have the same duties.

That said, the Senate does play a unique role in the functioning of the U.S. government. For example:

Impeachment: While the House of Representatives initiates impeachment proceedings against government officials, including the President, it is the Senate that investigates the charges and tries the cases against the officials, effectively acting as a prosecutor and jury. Since 1789, the Senate has tried 20 federal officials, including three presidents.

Cabinet, Ambassadorial and Judicial Nominations: The President has the power to appoint members of his presidential cabinet (including secretaries to the various agencies of the federal government), U.S. ambassadors to foreign countries and the United Nations, and justices of the Supreme Court and other federal judges. However, the Senate holds the power to vet and approve these appointments. Appointees who fail to receive Senate approval cannot assume their posts.

Treaties: While the President holds the power to negotiate and make treaties with foreign governments, the Senate must ratify these agreements, and the body does hold the power to amend treaties as it deems necessary.

Censure and Expulsion: Article 1, Section 5 of the U.S. Constitution gives both houses of Congress the right to punish members for “disorderly behavior.” In the Senate, members can be “censured” (a formal term essentially meaning condemnation or denouncement), which is a formal disapproval. The Senate, by a two-thirds majority, can also vote to expel a member for disorderly conduct, a far more severe punishment. Since 1789, the Senate has censured nine members and expelled 15.

Filibuster and Cloture: The procedure known as filibuster—essentially open debate used to delay or block a vote on legislation—has been employed numerous times throughout history. In 1957, Senator Strom Thurmond famously filibustered for more than 24 hours in an attempt to delay a vote on the Civil Rights Act of that year. His filibuster included a full reading of the Declaration of Independence. Since 1917, with the passage of Rule 22, the Senate can vote to end a debate with a two-thirds majority, in a procedure known as cloture. In 1975, the Senate modified the cloture rule to enable enacting of the tactic on a three-fifths majority (60 of the 100 members).

Investigations: Both houses of Congress can conduct formal investigations of wrongdoing on the part of the Executive Branch (the president and/or his cabinet) as well as other officials and agencies. One of the most famous Senate investigations involved the Watergate scandal, which led to the impeachment of President Richard M. Nixon in 1974.

Contested Elections: The Constitution also gives each house of Congress the power to be the judge of the “elections, returns and qualifications of its own members.” Since 1789, the Senate has developed procedures for judging the qualifications of its members and settling contested elections.

Senate Leadership

The Senate’s leadership also differs from that of the House of Representatives.

For example, in addition to being the first person to succeed the President, should the person elected to the position be unable to fulfill the role (as a result of death, illness or impeachment), one of the duties of the Vice President of the United States, who is elected to office on the same “ticket” as the President, is to serve as the “President of the Senate.”

In this role, the Vice President has no vote, unless a vote on legislation results in a 50-50 split. In this case, the Vice President casts the vote to effectively break the tie. Since 1870, no Vice President has had to perform this task more than 10 times during his term in office.

Like the House of Representatives, the Senate also has Majority and Minority Leaders. The Majority Leader represents the party with the majority of seats in the Senate. The Majority Leader coordinates with committee chairs and their party members to schedule debate on the Senate floor.

Both the Majority Leader and the Minority Leader, who represents the party with fewer seats in the Senate, also advocate for their respective party’s positions on various issues and pieces of legislation being debated in the body.

The current leaders of the Senate are Vice President Mike Pence and president pro tempore Chuck Grassley.


Origins and Development: The U.S Senate: United States Senate.
The Two Houses of the United States Congress: The Center on Representative Government, Indiana University.
Articles of Confederation: Digital History, University of Houston.