| 1920.0 | (Teddy Roosevelt president) |
| 1920.1 | League of Nations discussions; Red Army captures Odessa |
| 1920.2 | 19th Amendment: women's right to vote: Marconi opens first public broadcasting system in England |
| 1920.3 | Unemployment insurance introduced in England; Harding elected president; Pittsburgh radio braodcasts election results |
| 1920.4 | Russian civil war ends; Emergence of Gandhi in India; Rohrschock devises inkblot test; Submachine gun invented; First airmail flight SF -> NY |
| 1921.0 | (Harding president) |
| 1921.1 | First regular radio program in US |
| 1921.2 | Capital punishment abolished in Sweden; Discovery of bacteriophages |
| 1921.3 | Oberth writes `The Rocket into Interplanetary Space'; KKK becomes violently active |
| 1922.0 | (Harding president) |
| 1922.1 | Gandhi sentenced to 6 years in prison |
| 1922.2 | Joyce's Ulysses |
| 1922.3 | Mussolini forms fascist government; 1922.3 Self winding wristwatch |
| 1922.4 | USSR formed; First use of insulin for diabetes |
| 1923.0 | (Harding, then Coolidge president) |
| 1923.1 | First birth control clinic: Earthquake kills 120,000 in Japan, esp Tokyo |
| 1923.2 | Hubble discovers ''distance-indicating'' star in Andromeda nebula |
| 1923.4 | Teapot Dome scandal in DC; Harding dies; Coolidge succeeds; KKK violence increases |
| 1924.0 | (Coolidge president) |
| 1924.1 | Wave theory of matter |
| 1924.2 | US bill limits immigrants, excludes Japanese |
| 1924.3 | Will Rogers at height of fame; First insecticides; Leopold/Loeb trial for kidnap/murder |
| 1924.4 | Coolidge elected president |
| 1925.0 | (Coolidge president) |
| 1925.1 | Heisenberg and Bohr develop quantum mechanics |
| 1925.2 | Pauli exclusion principle on statistic structure of atoms |
| 1925.3 | Scopes `monkey trial' on teaching evolution |
| 1926.0 | (Coolidge president) |
| 1926.1 | Goddard fires first liquid fuel rocket; Heisenberg further develops quantum physics |
| 1926.2 | First 16mm movie film |
| 1927.0 | (Coolidge president) |
| 1927.1 | German economic system collapses |
| 1927.2 | Pavlov writes on `conditioned reflexes'; Lindbergh's flight to Paris |
| 1927.3 | Babe Ruth hits 60 home runs |
| 1928.0 | (Coolidge president) |
| 1928.1 | Beginning of first Soviet 5-year plan; Discovery of Penicillin |
| 1928.2 | Veronoff: `Conquest of Life' on gland transplanting; First scheduled TV broadcast; Amelia Earhart flies across Atlantic Ocean |
| 1928.3 | Color movies |
| 1928.4 | Herbert Hoover elected president |
| 1929.0 | (Hoover president) |
| 1929.1 | St. Valentine's Day gangland massacre in Chicago |
| 1929.2 | Graf Zeppelin flies around world; Estrone isolated; vitamin B1 discovered |
| 1929.3 | Quartz crystal clock for precise time keeping |
| 1929.4 | Hubble measures red shifts in spectra of extra-galactic nebulae; Stock market crash (Oct 28) |
| 1930.0 | (Hoover president) |
| 1930.1 | Pluto discovered; Photoflash bulb; First talk about `technocracy'; Artificial fabrics |
| 1931.0 | (Hoover president) |
| 1931.2 | Lansky discovers radio interference from Milky Way; Papal encyclical on `new social order'; Cyclotron invented; Deuterium discovered |
| 1931.3 | Submarine Nautilus under Arctic Ocean |
| 1931.4 | Al Capone jailed; Nonstop flight Tokyo - US; Fascists rise throughout western world |
| 1932.0 | (Hoover president) |
| 1932.1 | Hindenburg defeats Hitler for German presidency, but Nazis get 230 Reichstag seats; Discovery of positron and neutron; Lindbergh baby kidnapped; Famine in USSR begins, as does second five-year plan |
| 1932.2 | Earhart flies solo across Atlantic; Foundations of radio astronomy |
| 1932.4 | FD Roosevelt elected US President, calls for New Deal; Vitamin D discovered; Work begun on Golden Gate Bridge |
| 1933.0 | (F D Roosevelt president) |
| 1933.1 | FDR introduces `New Deal'; creates Public Works Administration; Hitler becomes chancellor and later dictator; Reichstag fire in Berlin |
| 1933.2 | First German concentration camps |
| 1933.3 | Chicago World's Fair (`century of progress'); Nazis gets 92% of German vote |
| 1933.4 | Starvation in USSR; 21st Amendment: repeal of prohibition |
| 1934.0 | (F D Roosevelt president) |
| 1934.2 | Hitler, voted Fuhrer, promotes assassinations in Germany and Austria |
| 1934.4 | Stalin begins bloody purge in USSR |
| 1935.0 | (F D Roosevelt president) |
| 1935.1 | Nazis repute Treaty of Versailles; First aircraft radar; First sulfa drug |
| 1935.3 | US Social Security Act |
| 1935.4 | CIO organized |
| 1936.0 | (F D Roosevelt president) |
| 1936.1 | German troops occupy Rhineland |
| 1936.3 | Spanish civil war begins; Hoover dam; Jesse Owens stars in Berlin Olympics; Life magazine begins |
| 1936.4 | Artificial heart; Mussolini and Hitler ally; King Edward VIII abdicates to marry US divorcee; Reelection of FDR; Hauptman convicted of killing Lindbergh baby; Johnstown PA flood |
| 1937.0 | (F D Roosevelt president) |
| 1937.1 | Death of Amelia Earhart |
| 1937.2 | FDR signs neutrality act; Insulin used for diabetes; Nylon patented; Hindenberg disaster, described live on radio |
| 1937.3 | Japanese seize Peking and other Chinese cities; Royal commission recommends establishment of Jewish and Arab states; First jet engine |
| 1938.0 | (F D Roosevelt president) |
| 1938.1 | Japanese install puppet government in China; Gas masks issued to English civilians |
| 1938.2 | Franco begins offensive in Spain; Germany occupies Sudeten in Czechoslovakia |
| 1938.3 | Ball point pen; Reber receives short waves from Milky Way |
| 1938.4 | Vitamins E and B6 |
| 1939.0 | (F D Roosevelt president) |
| 1939.1 | Barium obtained my bombarding uranium with neutrons; Possibility arises of splitting atom |
| 1939.2 | Death of Freud; Franco wins Spanish civil war |
| 1939.3 | Germany occupies Bohemia, Moravia, and Slovakia; Italy invades Albania; Germany invades Poland and World War II begins (Sep 1); England and France declare war (Sep 3) |
| 1939.4 | Nylon stockings on sale |
| 1940.0 | (F D Roosevelt president) |
| 1940.1 | War in Europe and Asia; Rationing in Britain; Germany invades Norway and Denmark; Churchill becomes Prime Minister; Giant cyclotron built in California; Penicillin becomes more practical, esp as an antibiotic |
| 1940.2 | Electron microscope; First helicopter flight; Germany invades Holland, Belgium, Luxembourg; Germans enter Paris (Jun 14) |
| 1940.3 | Battle of Britain begins: London blitz |
| 1940.4 | FDR reelected |
| 1941.0 | (FD Roosevelt president) |
| 1941.1 | Underwater photography; Construction begins on Panama Canal |
| 1941.2 | Germans invade Russia (Jun 22) |
| 1941.3 | Discovery of plutonium |
| 1941.4 | Japanese bomb Pearl Harbor (Dec 8); US and GB declare war on Japan (Dec 9); US declares war on Germany and Italy |
| 1942.0 | (FD Roosevelt president) |
| 1942.1 | Japan captures Dutch East Indies, Burma, Singapore; First automatic computer in US |
| 1942.2 | US bombs Tokyo; Nazis burn Lidice in Bohemia; Japanese-American internment |
| 1942.3 | Holocaust begins in concentration camps |
| 1942.4 | US attacks North Africa; Germans work on V2 rocket; First sustained nuclear reaction at U of Chicago; Testing of first US jet plane |
| 1943.0 | (F.D. Roosevelt president) |
| 1943.1 | Russians destroy German army east of Stalingrad |
| 1943.2 | Warsaw ghetto massacre |
| 1943.3 | Allies recapture much of north Africa; Allies invade Italy; Italy surrenders to Eisenhower; Allied round the clock bombing of Germany; Discovery of streptomycin US polio epidemic |
| 1944.0 | (F.D. Roosevelt president) |
| 1944.2 | D-Day landing on Normandy (Jun); VI bombs hit London |
| 1944.3 | V2 rockets hit London; US troops enter Germany |
| 1944.4 | FDR reelected; Battle of the Bulge begins at Ardenne; Vietnam declares independence from France |
| 1945.0 | (F.D. Roosevelt president; later Truman) |
| 1945.1 | Russians take Warsaw; Yalta conference |
| 1945.2 | FDR dies; Truman succeeds; UN Charter (Jun); Suicide of Hitler; Surrender of Germany (May); End of European War (May) |
| 1945.3 | First atomic bomb test in NM; US drops atomic bomb at Hiroshima (Aug); US drops atomic bomb at Nagasaki (Aug); Japan surrenders and World War II ends (Aug); War death toll: 35 million + 10 million in concentration camps |
| 1945.4 | Nationalists and communists fight in China; Nuremberg trials begin |
| 1946.0 | (Truman president) |
| 1946.1 | ENIAC computer dedicated |
| 1947.0 | (Truman president) |
| 1947.2 | Marshall Plan for reconstruction of Europe; UN announces plan to partition Palestine; Flying saucer reports in US |
| 1946.3 | Jackie Robinson signs baseball contract; Indian independence |
| 1947.4 | First supersonic flight; Invention of transistor |
| 1948.0 | (Truman president) |
| 1948.1 | University of Michigan wins Rose Bowl 49-0 over USC; Gandhi assassinated; Invention of LP record |
| 1948.2 | 200'' Mount Palomar telescope dedicated; Jewish state born |
| 1948.3 | Berlin airlift |
| 1948.4 | Narrow reelection of Truman; Kinsey Report on US sexual behavior |
| 1949.0 | (Truman president) |
| 1949.1 | Communist Mao Tse-tung wins rule of China: Chiang Kai-shek and his army flee to Formosa; USSR tests its first atomic bomb |
| 1949.2 | France grants independence to Vietnam; Britain recognizes independence of Ireland |
| 1949.3 | US launches guided missile; Israel admitted to UN; capital moved to Jerusalem; Apartheid policy established in South Africa; Berlin airlift ends |
| 1949.4 | Holland grants independence to Indonesia |
| 1950.0 | (Truman president) |
| 1950.1 | Communist Chinese forces occupy Tibet; Rise of Senator Joe McCarthy |
| 1950.2 | North Korea invades South Korea; Californium and Berkelium discovered; Einstein writes `General Theory of Relativity.' |
| 1950.3 | UN forces under Gen. MacArthur recapture Seoul |
| 1951.0 | (Truman president) |
| 1951.1 | Korean war continues; 22nd Amendment: presidential term limit |
| 1950.2 | Color TV introduced in US |
| 1951.3 | Peron reelected president of Argentina |
| 1951.4 | Electric power from atomic power |
| 1952.0 | (Truman president) |
| 1952.1 | Queen Elizabeth II succeeds to British throne; Contraception pill produced |
| 1952.4 | US test hydrogen bomb; Eisenhower elected US President |
| 1953.0 | (Eisenhower president) |
| 1953.1 | Tito elected president of Yugoslavia; Prehistoric paintings found in French caves |
| 1953.2 | Stalin dies, succeeded by Malenkov; Rosenbergs executed as atomic spies |
| 1953.3 | Korean armistice signed; Vietnamese rebels attack Laos; USSR explodes hydrogen bomb; Mt Everest first scaled |
| 1953.4 | Lung cancer linked to cigarette smoking |
| 1954.0 | (Eisenhower president) |
| 1954.1 | Jonas Salk inoculates Pittsburgh children against polio |
| 1954.2 | Vietnamese communists take Dien Bien Phu; US Supreme Court outlaws segregation in public schools; Senator McCarthy and House on Unamerican Activities bring their hunt to TV |
| 1954.3 | Roger Bannister breaks four-minute mile |
| 1954.4 | US Senate censures McCarthy |
| 1955.0 | (Eisenhower president) |
| 1955.2 | Peron resigns |
| 1955.3 | Einstein dies at age 86 |
| 1955.4 | Blacks in Montgomery boycott segregated city bus system |
| 1956.0 | (Eisenhower president) |
| 1956.1 | Rock and Roll in vogue; Tension in Middle East |
| 1956.2 | Khruschev denounces Stalinism; Actress Grace Kelly weds Prince Rainier of Monaco |
| 1956.3 | Sabin develops oral anti-polio vaccine |
| 1956.4 | Reelection of Eisenhower; Nixon Vice President; Emergence of Martin Luther King; Castro begins civil war against Batista in Cuba |
| 1957.0 | (Eisenhower president) |
| 1957.2 | Nobelium (element 102) discovered |
| 1957.4 | USSR launches Sputnik satellites; US bemoans their science inferiority; Eisenhower sends troops to Little Rock in high school desegregation crisis; Baseball Giants and Dodgers move from NY to California |
| 1958.0 | (Eisenhower president) |
| 1958.1 | Khruschev heads USSR; European Common Market officially begins |
| 1958.2 | DeGaulle elected president of France; Alaska becomes 49th state |
| 1958.3 | NASA established |
| 1958.4 | US launches moon rocket (doesn't get there) |
| 1959.0 | (Eisenhower president) |
| 1959.1 | Castro expels Batista from Cuba, expropriates US-owned sugar mills; USSR successful launches: one with 2 monkeys aboard, one reaches moon, one circles moon |
| 1959.3 | Hawaii becomes 50th state; Eisenhower halts steelworker and longshoremen strikes |
| 1960.0 | (Eisenhower president) |
| 1960.1 | Brezhnev becomes USSR premier |
| 1960.2 | USSR shoots down Gary Powers in a US spy plane over Russia; First US weather satellite; US nuclear submarine Triton circumnavigates earth underwater |
| 1960.3 | Former Gestapo chief Eichmann arrested; J F Kennedy debates Nixon on TV; Laser devises |
| 1960.4 | Brasilia built to become new capital of Brazil; Charles Van Doren admits perjury in quiz show inquiry; Kennedy elected US president |
| 1961.0 | (J F Kennedy president) |
| 1961.1 | Kennedy establishes Peace Corps as he had promised earlier on steps of UM Student Union; Yuri Gagarin orbits earth |
| 1961.2 | Alan Shepard makes first successful US manned space flight; CIA-backed Cuban exiles in US attempt futile (Bay of Pigs) invasion of Cuba; Kennedy takes blame for Bay of Pigs fiasco |
| 1961.3 | Berlin Wall constructed |
| 1962.0 | (J F Kennedy president) |
| 1962.1 | More US astronauts, including Glenn, Shepard and Schirra; Eichmann hanged after trial |
| 1962.2 | Rachel Carson writes ``Silent Spring'' |
| 1962.2 | Thalidomide causes children to be born with deformities |
| 1962.3 | US marshals enforce admission of James Meredith to University of Mississippi; US confronts USSR ships in blockade of Cuba |
| 1963.0 | (J F Kennedy; later L B Johnson) |
| 1963.1 | First female astronaut (USSR) |
| 1963.3 | Birmingham, Alabama race riots; MLK arrested; 200,000 hear MLK's I Have a Dream speech |
| 1963.4 | US supports Buddhist coup in Vietnam; Assassination of JFK by Lee Harvey Oswald (Nov 22); Lyndon Johnson (LBJ) sworn in as president; Ruby kills Oswald in front of TV audience; DeBakey uses artificial heart during heart surgery |
| 1964.0 | (L B Johnson president) |
| 1964.1 | ``Brain drain'' emigration of British scientists to US; Zanzibar (Tanzania), Zambia and later Kenya become republics; 24th Amendment: bans poll tax; Turks and Greeks fight over Cyprus |
| 1964.3 | US destroyer attacked off North Vietnam; Warren Commission says no conspiracy in JFK assassination; Kosygin replaces Khruschev as head of USSR; Race riots in US cities |
| 1964.4 | LBJ reelected |
| 1965.0 | (L B Johnson president) |
| 1965.1 | LBJ institutes Great Society Plan, under leadership of UM Economist Gardner Ackley; Malcolm X shot in NY; MLK leads Alabama march after racial violence in Selma, AL |
| 1965.2 | North Vietnam aircraft shoot down US jets; USSR and US spacewalks |
| 1965.3 | Severe race riots in Watts district of Los Angeles; Mariner 4 sends back many photos from above Mars |
| 1965.4 | Northeast US (including NYC) suffers power blackout; births increase 9 months later; US Students protest widening US involvement in Vietnam |
| 1966.0 | (L B Johnson president) |
| 1966.1 | DeGaulle begins second term as president of France; Indira Gandhi becomes Prime Minister of India |
| 1966.2 | USSR and US spacecraft make soft landings on moon |
| 1966.3 | Israel-Jordan forces fight; DeBakey implants artificial heart |
| 1967.0 | (L B Johnson president) |
| 1967.1 | Israel-Syria conflict; Three US astronauts die on launching pad |
| 1967.2 | US bombs Hanoi; Israel wins 6-Day War against Arab nations |
| 1967.3 | DeGaulle urges independence for Quebec; Death of Che Guevara; DC anti-war protest; LBJ appoints Thurgood Marshall to US Supreme Court; Black riots in Cleveland, Newark and Detroit; China explodes hydrogen bomb; First human heart transplant |
| 1967.4 | MLK leads anti-Vietnam War March in NYC; About 500,000 US troops in Vietnam |
| 1968.0 | (L B Johnson president) |
| 1968.1 | Viet Cong successful Tet counter-offensive; Sen. Robert Kennedy announces presidential campaign; Pres Johnson announces that he will not seek reelection |
| 1968.2 | MLK assassinated in Memphis; R F Kennedy assassinated in LA, just after victory speech for California primary |
| 1968.3 | Riots and police brutality mark Democratic convention in Chicago; Soviet troops invade Czechoslovakia to thwart independence drive |
| 1968.4 | Richard Nixon elected president; Apollo 7 orbits earth for 11 days with 3 astronauts; Apollo 8 orbits moon with 3 astronauts |
| 1969.0 | (Nixon president) |
| 1969.1 | Violent fighting begins in Northern Ireland; First supersonic flight by commercial SST Concorde |
| 1969.2 | Mariner space probes send back photos of Mars surface |
| 1969.3 | Woman killed as Sen Edward Kennedy's car plunges off bridge after party; Apollo 11 lands on moon; Astronaut Armstrong and crew walk on moon's surface |
| 1969.4 | US bans pesticide DDT; First `Moratorium' day of student protest against Vietnam War |
| 1970.0 | (Nixon president) |
| 1970.2 | US invades Cambodia; 4 students protesting the war at Kent State are killed by National Guard |
| 1970.3 | USSR lands unmanned Luna 16 and 17 on moon and Venera 7 on Venus; Cyclones kill 1/2 million in Pakistan; Apollo 13's troubled flight |
| 1971.0 | (Nixon president) |
| 1971.1 | Vietnam war spreads to Laos and Cambodia; US ping pong team hosted in China; Idi Amin starts Ugandan dictatorship; Lt. Calley found guilty in trial for My Lai massacre in Vietnam |
| 1971.2 | 26th Amendment allowing 18 year olds to vote; NY Times publishes Pentagon Papers detailing inside decisions regarding Vietnam |
| 1971.3 | Nixon freezes wages and prices; Crews of Apollo 14 and 15 explore moon's surface; cosmonauts die on reentry of Soyuz 11 to earth; Police storm Attica Prison, 10 guards and 32 prisoners killed |
| 1971.4 | USSR soft lands space capsule on Mars; Discovery of two new galaxies adjacent to Milky Way; US conducts large scale bombings of North Vietnam |
| 1972.0 | (Nixon presdent) |
| 1972.1 | Paris Peace Talks try to end Vietnam War; Nixon visits China and Russia |
| 1972.2 | Arrest of 5 burglars at Watergate Complex; administration covers up burglars' motives; Candidate George Wallace shot and paralyzed; Crews of Apollo 16 and 17 each spend about 3 days on moon |
| 1972.3 | Arab terrorists hit Munich Olympics; 11 Israeli sthletes killed |
| 1972.4 | After years of violence, Britain takes direct control of Northern Ireland; US mines North Vietnamese ports; Nixon reelected; Agnew vice president; By end of year, fewer than 24,000 US troops in Vietnam |
| 1973.0 | (Nixon president) |
| 1973.1 | Continued violence in Northern Ireland; Vietnam peace treaty; though some fighting continues |
| 1973.2 | Arabs and Israelis fight; Watergate scandal spreads to White House; Nixon's aides resign; Senate Watergate hearings on television; Pioneer 10 launched, will send back TV pictures from near surface of Jupiter; designated hitter rule in baseball |
| 1973.3 | Nixon turns over tape recordings of all White House conversations -- with critical gaps; Vice President Agnew resigns after tax evasion charge |
| 1973.4 | Gerald Ford new vice president; Arab oil producing nations embargo shipments to west, precipating major oil crisis and economic crises; Peron and wife elected pres and vice pres of Argentina; OJ Simpson sets 1 year football rushing record; |
| 1974.0 | (Nixon president: later G Ford) |
| 1974.1 | World wide inflation rises after oil crisis; Kissinger mediates war between Israel and Syria; Kidnapping of heiress Patricia Hearst by Symbionese Liberation Army, later joins them in bank robbery; Year round daylight savings time to conserve fuel |
| 1974.2 | Peron dies, succeeded by his wife; North Ireland terrorism spreads to London; Turks and Greeks battle in Cyprus; Mariner 10 sends back detailed pictures of Venus and Mercury; USSR probe finds much water vapor on Mars; India test nuclear bomb |
| 1974.3 | Aaron breaks Ruth's lifetime home run record; Nixon resigns in wake of Watergate Crisis; Ford now president; Ford pardons Nixon and Vietnam War draft evaders; Streaking becomes a fad |
| 1975.0 | (Ford president) |
| 1975.2 | Last US personnel leave Vietnam; Khmer Rouge take over Cambodia; Galaxy 3C123 discovered: 8 billion light years away and 5-10 times larger than Milky Way |
| 1975.3 | 2 assassination attempts on President Ford; Joint US/USSR space endeavors. |