April 30, 1975. Two years after the last U.S. troops left Vietnam in 1973, the South Vietnamese government surrenders Saigon, the capital city, to invading communist North Vietnamese troops who rename the city Ho Chi Minh City. Thousands of South Vietnamese who have some association with the United States or with the South Vietnamese government try to escape the new communist regime by boat or by plane.

April, 1975. Nineteen-year-old Bill Gates forms Microsoft with his friend, Paul Allen. Their first computer software program is Altair-BASIC for the Altair 8800 microcomputer.

April, 1975. The new communist Khmer Rouge government, led by dictator Pol Pot, embarks on a program of radical social transformation. The Khmer Rouge will ban all religion and especially target Buddhist monks, Muslims, Christians, Western-educated intellectuals, educated people in general, people who have contact with Western countries or with Vietnam, disabled people, and the ethnic Chinese, Laotians and Vietnamese. The four-year period of Khmer Rouge rule will see the deaths of approximately two million Cambodians as a combined result of political executions, starvation, and forced labour. Due to the large numbers, the deaths during the rule of the Khmer Rouge are often considered a genocide, and commonly known as the Cambodian Holocaust or Cambodian Genocide.

June 5, 1975. The Suez Canal opens for the first time since the Six-Day War in 1967.

July 17, 1975. American Apollo and Russian Soyuz spacecraft dock in space, and astronaut Tom Stafford and cosmonaut Alexei Leono shake hands 140 miles above the Atlantic Ocean in the first joint Russian/US space venture.

August 1, 1975. The Helsinki Accords, which officially recognize Europe’s national borders and respect for human rights, are signed in Finland. Thirty-five nations, including the USA, Canada, and all European states except Albania and Andorra, sign the declaration in an attempt to improve relations between the Communist bloc and the West.

September 16, 1975. Papua New Guinea gains its independence from Australia.

November, 1975. The United Kingdom opens its first underwater pipeline for North Sea oil.

November, 1975. The nation of Angola in southern Africa gains its independence from Portugal and almost immediately is torn by civil war between at least four political groups vying for power in the country. The Marxist (Communist) group, MPLA, receives aid from the SOviet Union and from Cuba, while other factions are supported by the U.S. or by South Africa.

November 22, 1975. Don Juan Carlos Borbon y Borbon becomes King of Spain after the death of General Francisco Franco who has ruled Spain since 1939. Spain’s government will transition to a constitutional democratic monarchy.

February, 1974. Soviet author Alexander Solzhenitsyn is exiled from the Soviet Union after publication of his epic novel The Gulag Archipelago, a book critical of the communist government in the USSR. Solzhenitsyn was awarded the Nobel Prize in Literature in 1970.

March 8, 1974. Charles de Gaulle Airport opens in Paris, France.

April 25, 1974. Carnation Revolution: A coup in Portugal restores democracy. Despite repeated appeals from the revolutionaries on the radio asking the population to stay home, thousands of Portuguese descend on the streets, mixing with the military insurgents. The name Carnation Revolution comes from the fact that no shots are fired, and the celebrating Portuguese citizens put carnation flowers on the soldiers’ guns and on their uniforms.

May 17, 1974. Dublin and Monaghan bombings: The Protestant terrorist group, the Ulster Volunteer Force (UVF), explode numerous bombs in Dublin and Monaghan, in the Republic Of Ireland. The attacks kill 33 civilians and wound almost 300.

May 18, 1974. India successfully detonates its first nuclear weapon, becoming the 6th nation to do so.

August 8, 1974. President Richard Nixon, facing impeachment by Congress over the Watergate scandal and cover-up, becomes the first U.S. president to reign from office. Vice-President Gerald Ford will become the new president.

September 12, 1974. Emperor Haile Selassie of Ethiopia is deposed by the Derg, a military committee which soon embraces communism and will rule in Ethiopia for the next thirteen years.

November 21, 1974. In Birmingham, England, IRA (Irish Republican Army) terrorists bomb 2 pubs, killing 21 people.

Rubik’s Cube, a 3-D mechanical puzzle, is invented sometime in 1974 by Hungarian sculptor and professor of architecture ErnÅ‘ Rubik. As of January 2009, 350 million cubes have been sold worldwide, making Rubik’s Cube the world’s top-selling puzzle game.