Charles Schenck wrote a pamphlet arguing that the military draft was immoral and unconstitutional. For that he was sentenced to six months in prison under the Espionage Act of 1917. In the case of Schenck v. United States (1919), a unanimous Supreme Court upheld the act against Schenck's First Amendment challenge and introduced the "clear and present danger" test into the Court's free speech jurisprudence.