Schenck v. United States (1919) helped define the limits of the First Amendment right to free speech, particularly during wartime. It created the “clear and present danger” standard, which explains when the consequences of speech allow the government to limit it. In this case, the Court chose to unanimously uphold activist Charles Schenck’s conviction after he distributed leaflets urging young men to resist the draft during World War I.

As general secretary of the Socialist Party in Philadelphia, Schenck prepared leaflets that urged young men to “assert your rights” in the face of conscription. In the midst of the First World War, the U.S. government regarded calls for draft resistance as dangerous to national security. Charles Schenck was arrested under the Espionage Act of 1917, which prohibited “disloyal” acts. He was convicted and appealed to the Supreme Court, arguing that his actions were protected as part of his First Amendment freedom of speech. A wartime Court felt differently and ruled to uphold the Act. Justice Oliver Wendell Holmes, Jr., in this famous opinion, compared Schenck’s actions to “falsely shouting fire in the theatre and causing a panic.” This expression is still widely used as an example of the limits of free speech.