North Vietnam launches a large conventional offensive on three fronts in the South, including prolonged fighting at Quảng Trị.
U.S. President Richard Nixon's visit opens the way to normalised relations between the United States and China.
The United States carries out intensive B-52 bombing of Hanoi and Haiphong for twelve days, known in Vietnam as the "Điện Biên Phủ in the air".
Ray Tomlinson sends the first email between computers on ARPANET, choosing the @ sign to separate user and host names.
Intel introduces the 4004, the first commercially available single-chip microprocessor, paving the way for personal computers.
The United States, North and South Vietnam and the Provisional Revolutionary Government sign an agreement ending direct US involvement in the war.
The last US combat units leave South Vietnam under the terms of the Paris Peace Accords.