Reprint of the second edition. Originally Cambridge, Harvard University Press, 1967. xviii, 634 pp. A rewritten and expanded version of his seminal Freedom of Speech (1920) which established modern First Amendment theory, Free Speech in the United States (1941), became a foremost text of U.S. libertarian thought. It considers the social necessity of free speech in the United States from the 1920's through 1941. Discusses freedom of speech in the Constitution, relevant cases in the Supreme Court under Hughes, war-time prosecutions, legislation against sedition, and more. This leading treatise on civil liberties influenced the jurisprudence of Oliver Wendell Holmes, Jr. and Louis Brandeis.