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The United States Constitution

Resources for researching the history, drafting, interpretation, and other elements of the U.S. Constitution.


The Bill of Rights is the name given to the first ten amendments to the Constitution. The amendments, which were intended to expand the Constitution's protection of individual liberties, were written by James Madison and ratified by the states in 1791. The full text of the Bill of Rights can be viewed here.

For a more comprehensive overview of the development of the Bill of Rights, please see the library's First Amendment Research Guide.

The First Amendment

For a very detailed discussion of the history, meaning and interpretation of the First Amendment, please see the library's First Amendment Research Guide.

The Second Amendment

A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.

  • The intent and meaning of the Second Amendment has been and still is hotly debated. Everything from the definition of "militia" to what the Founding Fathers might have considered "arms" is the subject of academic and popular controversy.
  • There is considerable information out there on all sides of the debate; for some basic discussion, see the National Constitution Center's Second Amendment page.

The Third Amendment

No Soldier shall, in time of peace be quartered in any house, without the consent of the Owner, nor in time of war, but in a manner to be prescribed by law.

  • The Third Amendment was adopted to address one of the most egregious abuses the British Army engaged in during the Revolutionary War - forcing private homes and businesses to house British troops and pay the costs out of their own pockets.
  • This is among the least interpreted provisions of the Bill of Rights. The U.S. Supreme Court has never given it extensive analysis, and Congress has never invoked the legal authority to authorize quartering.
  • To find out more, see the National Constitution Center's page here.

The Fourth Amendment

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

  • This Amendment has had a massive effect on the operation of the American criminal justice system. It restricts what law enforcement can do and what kind of information they can collect about citizens. The Amendment applies to everyone, from local police officers to federal agencies like the FBI and NSA.
  • Although it has always affected the everyday activities of police, the Fourth Amendment has become more prominent in the last few years with the rise of sophisticated information-collecting devices like drones. These new technologies have prompted a vigorous debate about what kind of information is protected under the Constitution.

For more, see the National Constitution Center.

The Fifth Amendment

No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.

  • The Fifth Amendment covers several different topics. First, it guarantees several protections for those accused of crimes - if they are charged under federal law, a grand jury must indict them; it enshrines the "double jeopardy" rule, which prevents the government from re-charging a person with the same crime if they've already been found innocent once; and it prohibits the government from forcing a person charged with a crime to testify about the crime in court. (This is why, if someone accused of a crime refuses to talk about it, they're said to be "pleading the Fifth".)
    • These three protections are considered to be critical to balancing the rights of the accused and the effective functioning of the justice system, and they are among the most litigated provisions of the Constitution.
  • Second, the Fifth Amendment requires governments to consistently and fairly apply the law. This rule, often called the "due process clause", has been interpreted by the Supreme Court to grant a variety of protections to citizens.
  • Finally, the Fifth Amendment protects private property rights by forbidding the government from seizing a person's property without giving them fair compensation for it. Although this clause applies to all kinds of property, it's mostly invoked when the government attempts to seize land. Such a seizure, often called "eminent domain", is a major area of controversy. The 2005 case of Kelo v. New London is one of the most famous examples of the Supreme Court interpreting this amendment.

If you're interested in a detailed analysis of this Amendment, see this page.

The Sixth Amendment

In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence.

  • Like the Fifth Amendment, the Sixth Amendment incorporates several rights related to criminal prosecutions. These rights are intended to protect the integrity of the adversarial process and make sure that criminal defendants are treated fairly. All of the Sixth Amendments's clauses have been heavily litigated; for more background on each of them, see this page.

The Seventh Amendment

In Suits at common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury shall be preserved, and no fact tried by a jury, shall be otherwise re-examined in any Court of the United States, than according to the rules of the common law.

  • While the Sixth Amendment protects the right of trial by jury in all criminal cases, it does not cover civil cases. The Seventh Amendment fills that gap by preserving the right to a jury trial in virtually every civil case. This is very unusual - most countries, even those that are part of the English legal tradition, do not require juries in civil suits.
  • This Amendment has a complicated legal history. For a detailed examination of its historical roots and modern interpretation, see the National Constitution Center.

The Eighth Amendment

Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted.

  • The Eighth Amendment is modeled after very similar provisions in the 1689 English Bill of Rights and the 1776 Virginia Declaration of Rights.
  • This Amendment is the last of the Bill of Rights' criminal justice protections. It has two clauses. The first, the bail provision, prohibits the government from essentially jailing defendants indefinitely by requiring them to pay either a bail amount (before trial) or a fine (upon a conviction) that they cannot possibly afford.
  • The second clause contains four of the most hotly contested words in the Constitution: "cruel and unusual punishment". The exact meaning of this phrase is a topic of great controversy, especially in the wake of changing social attitudes towards punishments like the death penalty.
  • For more historical background on both of these clauses, see the National Constitution Center page here.

The Ninth Amendment

The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.

  • This Amendment is unusual in that it states how the Constitution is to be interpreted. It was intended to prevent the government from arguing that if a right is not mentioned in the Constitution, it isn't protected and may be restricted. This Amendment undercuts that claim by explicitly stating that other rights exist and are valid. What, exactly, those rights are is not stated, and that has given rise to many different interpretations.

For more, including a detailed discussion of why the Ninth Amendment was written, see this page.

The Tenth Amendment

The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.

  • This, the final amendment of the Bill of Rights, attempts to limit the power of the federal government by granting the states or the citizens every power that isn't explicitly listed in the Constitution. This was intended to prevent the federal government from trying to take powers it wasn't intended to have.
  • This Amendment is the source of many ongoing controversies involving state vs. federal power. For a detailed history, see the National Constitution Center's page here.