First Amendment, amendment (1791) to the Constitution of the United States that is part of the Bill of Rights and reads,

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

The clauses of the amendment are often called the establishment clause, the free exercise clause, the free speech clause, the free press clause, the assembly clause, and the petition clause.

The First Amendment, like the rest of the Bill of Rights, originally restricted only what the federal government may do and did not bind the states. Most state constitutions had their own bills of rights, and those generally included provisions similar to those found in the First Amendment. But the state provisions could be enforced only by state courts.

In 1868, however, the Fourteenth Amendment was added to the U.S. Constitution, and it prohibited states from denying people liberty without due process. Since then the U.S. Supreme Court has gradually used the due process clause to apply most of the Bill of Rights to state governments. In particular, from the 1920s to the 40s the Supreme Court applied all the clauses of the First Amendment to the states. Thus, the First Amendment now covers actions by federal, state, and local governments. The First Amendment also applies to all branches of government, including legislatures, courts, juries, and executive officials and agencies. This includes public employers, public university systems, and public school systems.

The First Amendment, however, applies only to restrictions imposed by the government, since the First and Fourteenth amendments refer only to government action. As a result, if a private employer fires an employee because of the employees speech, there is no First Amendment violation. There is likewise no violation if a private university expels a student for what the student said, if a commercial landlord restricts what bumper stickers are sold on the property it owns, or if an Internet service provider refuses to host certain Web sites.

Legislatures sometimes enact laws that protect speakers or religious observers from retaliation by private organizations. For example, Title VII of the federal Civil Rights Act of 1964 bans religious discrimination even by private employers. Similarly, laws in some states prohibit employers from firing employees for off-duty political activity. But such prohibitions are imposed by legislative choice rather than by the First Amendment.

The freedoms of speech, of the press, of assembly, and to petitiondiscussed here together as freedom of expressionbroadly protect expression from governmental restrictions. Thus, for instance, the government may not outlaw antiwar speech, speech praising violence, racist speech, pro-communist speech, and the like. Nor may the government impose special taxes on speech on certain topics or limit demonstrations that express certain views. The government also may not authorize civil lawsuits based on peoples speech, unless the speech falls within a traditionally recognized First Amendment exception. This is why, for example, people may not sue for emotional distress inflicted by offensive magazine articles about them, unless the articles are not just offensive but include false statements that fall within the defamation exception (see below Permissible restrictions on expression).

The free expression guarantees are not limited to political speech. They also cover speech about science, religion, morality, and social issues as well as art and even personal gossip.

Freedom of the press confirms that the government may not restrict mass communication. It does not, however, give media businesses any additional constitutional rights beyond what nonprofessional speakers have.

Freedom of petition protects the right to communicate with government officials. This includes lobbying government officials and petitioning the courts by filing lawsuits, unless the court concludes that the lawsuit clearly lacks any legal basis.

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First Amendment | Contents & Supreme Court Interpretations | Britannica.com