A Centenary for Free Speech

Americans may take free speech for granted, but they couldn’t do so a century ago. Courts convicted newspapermen, pamphleteers and politicians for nothing more—and sometimes less—than trying to sway the public against U.S. involvement in World War I. On Nov. 10, 1919, the Supreme Court affirmed the conviction of antiwar protesters under a law that made it a crime to “hinder” the war effort. But a dissent in Abrams v. U.S. laid the foundation for today’s robust protection of controversial speech.

The idea that speech could pose a “clear and...