History: 20th Century

26th President of the United States (1901–1909)

27th President of the United States (1909–13)

28th president of the United States (1913–1921)

29th President of the United States (1921–1923)

30th President of the United States (1923–29)

31st President of the United States (1929–33)

32nd President of the United States (1933–1945)

33rd President of the United States (1945-1953)

34th President of the United States (1953-1961)

35th President of the United States (1961-1963)

36th President of the United States (1963–1969)

37th President of the United States (1969–74)

38th president of the United States (1974–77)

39th president of the United States (1977–81)

40th president of the USA (1981-89)

41st President of the United States (1989–1993)

42nd president of the United States (1993-2001)

American clergyman and civil-rights leader.

A leading figure in the second wave of U.S. feminism.

American politician, U.S. Attorney General (1961-64), b. Brookline, Mass., younger brother of President John F. Kennedy and son of Joseph P. Kennedy.

Case decided by the U.S. Supreme Court in 1954; Linda Brown was denied admission to her local elementary school in Topeka because she was black.

Ideological, political, and economic tensions from 1945 to 1989 between the USSR and Eastern Europe on the one hand and the USA and Western Europe on the other.

War 16 January-28 February 1991 between Iraq and a coalition of 28 nations led by the USA; The invasion and annexation of Kuwait by Iraq on 2 August 1990 provoked a build-up of US troops in Saudi Arabia, eventually totalling over 500,000.

War from 1950 to 1953 between North Korea (supported by China) and South Korea, aided by the United Nations (the troops were mainly US).

Case decided in 1973 by the U.S. Supreme Court. Along with Doe v. Bolton, this decision legalized abortion in the first trimester of pregnancy.

A research programme, originally managed by NASA’s Ames Research Center, aimed at using large radio telescopes to detect artificially generated radio signals coming from interstellar space.

Oil reserve scandal that began during the administration of President Harding.

The severe economic crisis supposedly precipitated by the U.S. stock-market crash of 1929; Although it shared the basic characteristics of other such crises (see depression), the Great Depression was unprecedented in its length and in the wholesale poverty and tragedy it inflicted on society.

Demonstrations, marches, and acts of civil disobedience in protest to US involvement in the Vietnam War (1954-75), beginning around 1965.

War from 1954 to 1975 between communist North Vietnam and US-backed South Vietnam, in which North Vietnam aimed to conquer South Vietnam and unite the country as a communist state. North Vietnam was supported by communist rebels from South Vietnam, the Vietcong.

The New York Stock Exchange in 1929, where panic-selling of shares after a prolonged period of speculation brought about a worldwide economic crisis.

War between the Central European Powers (Germany, Austria-Hungary, and allies) on one side and the Triple Entente (Britain and the British Empire, France, and Russia) and their allies, including the USA (which entered in 1917), on the other side.

War between Germany, Italy, and Japan (the Axis powers) on one side, and Britain, the Commonwealth, France, the USA, the USSR, and China (the Allies) on the other.

US legislation that outlawed discrimination on the grounds of a person's colour, race, national origin, religion, or sex.

Government study of U.S. involvement in Southeast Asia. Commissioned by Secretary of Defense Robert S. McNamara in June, 1967, the 47-volume, top secret study covered the period from World War II to May, 1968.

Events following the seizure of the American embassy in Tehran by Iranian students on Nov. 4, 1979; The overthrow of Muhammad Reza Shah Pahlevi of Iran by an Islamic revolutionary government earlier in the year had led to a steady deterioration in Iran-U.S. relations.

Secret arrangement in the 1980s to provide funds to the Nicaraguan contra rebels from profits gained by selling arms to Iran; The Iran-contra affair was the product of two separate initiatives during the administration of President Ronald Reagan.

Demonstrations, marches, and acts of civil disobedience in protest to US involvement in the Vietnam War (1954–75), beginning around 1965. Anti-war sentiment arose from the question of the morality of participation in what many regarded as a civil war; the growing human and environmental costs; and doubts that the US war effort would succeed

US movement especially active during the 1950s and 60s that aimed to end segregation and discrimination against blacks, as well as affirm their constitutional rights and improve their status in society.

Statutory limitations placed on the number of terms officeholders may serve; Focusing especially on members of the U.S. Congress, term limits became an important national political issue during the late 1980s and early 90s and have been vigorously debated.

Period of political persecution during the 1950s, led by US senator Joe McCarthy, during which many public officials and private citizens were accused of being communists or communist sympathizers.

Reduction of a country's weapons of war.