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.