This introduction reframes the history of the U.S. Supreme Court decision Hague v. CIO (1939) that guaranteed speech and assembly rights in public municipal forums under federal law for the first time. It lifts the story out of standard treatment as a product of police repression of labor organizers by city boss Frank Hague, exploring instead the case’s broader roots in multiple changes in city governance, policing, the labor movement, civil liberties law, and anticommunism and antifascism politics of the late New Deal era. It urges examination of all sides of the controversy, winners and losers, scrutinizing evidence beyond antiboss sources, including varied newspapers, municipal reports, trial transcripts, labor archives, and federal court records. It views the case as part of a constitutional watershed.