This section of the Timeline of United States history concerns events from 1930 to 1949.

1930s

• 1930 - Hawley-Smoot tariff
• 1931 - Empire State Building opens
• 1931 - Japan invades Manchuria
• 1932 - Stimson Doctrine
• 1932 - Norris-Laguardia Act
• 1932 - Bonus Army marches on DC
• 1932 - Amelia Earhart flies across Atlantic Ocean
• 1932 - Norris LaGuardia Anti Injunction Bill
• 1932 - Reconstruction Finance Corporation
• 1933 - 20th Amendment
• 1933 - Franklin Delano Roosevelt becomes President
• 1933 - Agricultural Adjustment Act
• 1933 - Civil Works Administration
• 1933 - Civilian Conservation Corps
• 1933 - Farm Credit Administration
• 1933 - Home Owners Loan Corporation
• 1933 - Tennessee Valley Authority
• 1933 - Public Works Administration
• 1933 - National (Industrial) Recovery Act
• 1933 - Giuseppe Zangara kills Anton Cermak
• 1933 - Frances Perkins appointed United States Secretary of Labor
• 1933 - Montevideo Conference
• 1933 - 21st Amendment
• 1933 - Japan and Germany withdraw from League of Nations
• 1933 - Good Neighbor Policy announced
• 1934 - Glass-Steagal Act
• 1934 - Securities and Exchange Commission
• 1934 - Federal Housing Administration
• 1934 - Johnson Act
• 1934 - Reciprocal Trade Agreements Act
• 1934 - Tydings-McDuffie Act
• 1934 - John Dillinger killed
• 1934 - Indian Reorganization Act
• 1934 - Share the Wealth society founded by Huey Long
• 1935 - Works Progress Administration
• 1935 - Neutrality Act
• 1935 - Motor Carrier Act
• 1935 - Social Security Act
• 1935 - Schechter Poultry Corporation v. US
• 1935 - National Labor Relations Act
• 1935 - Huey Long assassinated
• 1935 - Congress of Industrial Organizations formed
• 1935 - Alcoholics Anonymous founded
• 1935 - Fair Labor Standard Act - sets minimum wage and hours
• 1935 - Revenue Act
• 1936 - Robinson Patman Act
• 1936 - Life Magazine begins
• 1936 - Butler v. US
• 1936 - London Conference on disarmament
• 1937 - Neutrality Acts
• 1937 - Hindenburg disaster
• 1937 - Japanese planes sink Panay in China
• 1937 - Golden Gate bridge completed
• 1938 - Wheeler Lea Act
• 1938 - Fair Labor Standards Act
• 1939 - Hatch Act
• 1938 - Orson Welles' The War of the Worlds broadcast
• 1939 - Germany invades Poland; World War II begins
• 1939 - Cash and Carry

The USS Arizona, aflame and sinking, on December 7, 1941

1940s

• 1940 - Selective Service Act
• 1940 - Alien Registration (Smith) Act
• 1941 - Lend Lease Act
• 1941 - Attack on Pearl Harbor
• 1941 - U.S. enters World War II
• 1941 - Atlantic Charter
• 1941 - Japanese internment begins
• 1942 - Office of Price Administration
• 1942 - Cocoanut Grove fire
• 1942 - Congress of Racial Equality
• 1942 - Revenue Act of 1942
• 1942 - U.S.-controlled Commonwealth of the Philippines conquered by Japanese forces
• 1943 - Office of Price Administration established
• 1943 - Detroit, Michigan race riots
• 1943 - Cairo Conference
• 1943 - Casablanca Conference
• 1943 - Tehran Conference
• 1944 - Bretton Woods Conference
• 1944 - Dumbarton Oaks Conference
• 1944 - GI Bill of Rights
• 1944 - D-Day
• 1945 - Yalta Conference
• 1945 - Battle of the Bulge
• 1945 - U.S. takes Okinawa
• 1945 - U.S. joins the United Nations
• 1945 - Nationwide labor strikes due to inflation; OPA disbanded
• 1945 - atomic bomb dropped on Hiroshima and Nagasaki
• 1945 - Germany and Japan surrender, ending World War II
• 1945 - Potsdam Conference
• 1945 - Franklin Delano Roosevelt dies
• 1945 - Harry S. Truman becomes President
• 1946 - Winston Churchill's Iron Curtain speech
• 1946 - Benjamin Spock's Child Care book published
• 1946 - Employment Act
• 1946 - Atomic Energy Act
• 1946 - Civil Rights Commission
• 1946 - Philippines regain their independence from the U.S.
• 1947 - Presidential Succession Act
• 1947 - Taft Hartley Act
• 1947 - National Security Act
• 1947 - General Agreement on Tariffs and Trade
• 1947 - The Marshall Plan
• 1947 - Truman Doctrine
• 1947 - Federal Employee Loyalty Program
• 1947 - Jackie Robinson breaks color barrier in baseball
• 1948 - Berlin Blockade
• 1948 - Election of 1948: Truman defeats Dewey
• 1948 - Truman desegregates armed forces
• 1948 - Organization of American States: Alliance of North America and South America
• 1948 - Alger Hiss Case
• 1948 - Nuremberg trials
• 1949 - North Atlantic Treaty Organization (NATO) formed
• 1949 - In China, Communists under Mao Zedong force Chiang Kai-shek's KMT government to retreat to Taiwan
• 1949 - Russia tests first atomic bomb
• 1949 - Department of War becomes Department of Defense
• 1949 - Germany divided into East and West
• 1949 - Truman attempts to continue FDR's legacy with his Fair Deal, but most acts don't pass
• 1949 - Dystopian future novel Nineteen Eighty-Four published by George Orwell