Wikipedia:Selected anniversaries/April 3
- 1882 – Jesse James, an outlaw in the American Old West, was shot in the back and killed for a bounty of US$5,000.
- 1895 – The libel trial instigated by Irish author Oscar Wilde began, eventually resulting in Wilde's arrest, trial and imprisonment on charges of homosexuality.
- 1922 – Joseph Stalin became the first General Secretary of the Communist Party of the Soviet Union.
- 1948 – The Marshall Plan (poster pictured), an economic recovery program established by U.S. Secretary of State George Marshall to assist the post-World War II re-building of Europe, was signed into law.
- 1971 – The Japanese tokusatsu television series Kamen Rider premiered, marking the beginning of the long-running Kamen Rider franchise.
- 1973 – On a New York City street, Motorola researcher Martin Cooper made the first public call on a handheld mobile phone.