On this day in history April 3,
- 1973 – Martin Cooper of Motorola makes the first handheld mobile phone call to Joel S. Engel of Bell Labs, though it took ten years for the DynaTAC 8000X to become the first such phone to be commercially released.
- 1974 – The Super Outbreak occurs, the second biggest tornado outbreak in recorded history (after the April 25–28, 2011 tornado outbreak). The death toll is 315, with nearly 5,500 injured.
- 1975 – Bobby Fischer refuses to play in a chess match against Anatoly Karpov, giving Karpov the title of World Champion by default.
- 1981 – The Osborne 1, the first successful portable computer, is unveiled at the West Coast Computer Faire in San Francisco.
- 1996 – Suspected “Unabomber” Theodore Kaczynski is captured at his cabin in Montana, United States.
- 1996 – A United States Air Force airplane carrying United States Secretary of Commerce Ron Brown crashes in Croatia, killing all 35 on board.
- 1997 – The Thalit massacre begins in Algeria; all but one of the 53 inhabitants of Thalit are killed by guerrillas.