Clear and present danger is a doctrine used to test whether limitations may be placed on First Amendment free speech rights. It was established in the case of Schenck v. United States, 249 U.S. 47 (1919). Charles Schenck, general secretary of the American Socialist Party was arrested and convicted for sending 15,000 anti-draft circulars through the mail to men scheduled to enter the military service. The circular called the draft law a violation of the 13th Amendment's prohibition of slavery. It went on to urge draftees not to "submit to intimidation," but to "petition for repeal" of the draft law.
The government accused Schenck of illegally interfering with military recruitment under the espionage act. Schenck admitted that he had sent the circulars, but argued that he had a right to do so under the First Amendment and was merely exercising his freedom of speech. Justice Oliver Wendell Holmes held that Mr. Schenck was not covered by the First Amendment since freedom of speech was not an absolute right. There were times, Holmes wrote, when the government could legally restrict speech. According to Justice Holmes, that test is "whether the words...are used in such circumstances as to create a clear and present danger."