Oliver Wendell Holmes Jr. remains one of the most influential of American legal philosophers. His formulation of the “clear and present danger” test regarding the right to free speech in his opinion in Schenck v. United States, which was further refined in his dissent in Abrams v. United States, set the stage for the development of free speech law in America. Charles Schenck, secretary-general of the Socialist Party of America, had been charged with printing and distributing antidraft literature, thus violating the Espionage Act of 1917. He appealed his conviction on First Amendment grounds, but in its 1919 decision the Supreme Court upheld the constitutionality of the Espionage Act and rejected the First Amendment protection of free speech—judging the legality of speech according to its tendency to provoke illegal acts.