In Schenck v. United States (1919), the Supreme Court invented the famous "clear and present danger" test to determine when a state could constitutionally limit an individual's free speech rights under the First Amendment.^[PBS. " Schenck v. U.S. (1919)." PBS. http://www.pbs.org/wnet/supremecourt/capitalism/landmark_schenck.html (accessed July 27, 2014).]