Truman signs Administrative Procedure Act, establishing public comment and judicial review requirements for federal agencies

President Truman signed the Administrative Procedure Act on June 11, 1946, establishing the foundational rules governing how federal agencies create regulations and make decisions. The APA required agencies to publish proposed rules, collect public comment in good faith, and provide reasoned explanations for major decisions. Courts gained authority to invalidate agency action found to be arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.