The FBI investigation into possible Espionage Act violations by former president Donald J. Trump for keeping top-secret documents at his Florida resort, has sparked curiosity in a WWI-era law rarely used to prosecute actual spies. In the 1950s, Julius and Ethel Rosenberg were tried, convicted, and executed under the Espionage Act for sharing top-secret information about the atomic bomb with the Soviet Union. They were the only American citizens ever executed as spies during peacetime, and their case remains controversial to this day. But, for the most part, the Espionage Act has rarely been used to punish espionage. In this episode, historian Christopher Capozzola discusses the law’s sordid origins. Congress passed it in a climate of xenophobia and anti-Red hysteria in 1917, the year the U.S. entered the First World War. But because many Americans opposed fighting in what they viewed as a war between European colonial powers, Congress included provisions allowing the federal government to crack down on dissent. Socialists, immigrants, peace activists, newspapers, and early filmmakers were targeted in this shameful chapter of American history.