- April 20, 1916 (103 years ago)
- •The Chicago Cubs play their first game at Weeghman Park (currently Wrigley Field), defeating the Cincinnati Reds 7-6 in 11 innings
- April 20, 1926 (93 years ago)
- •Western Electric and Warner Bros. announce Vitaphone, a process to add sound to film.
- April 20, 1999 (20 years ago)
- •Eric Harris and Dylan Klebold kill 13 people and injure 24 others before committing suicide at Columbine High School in Jefferson County, Colorado.
- April 20, 2008 (11 years ago)
- •Danica Patrick wins the Indy Japan 300 becoming the first female driver in history to win an Indy car race.