April 21st
- 1910 – Mark Twain died, aged 74.
- 1933 – Supernatural went to theaters.
- 1935 – El fantasma del convento went to theaters (US).
- 1937 – Ghost Party first aired on the radio.
- 1961 – The Rip Van Winkle Caper first aired on television.
- 1966 – Herman's Lawsuit first aired on television.
- 1989 – Pet Sematary went to theaters.