Events
- 1794 - The government of the United States establishes a permanent United States Navy and authorizes the building of six frigates.
- 1814 - War of 1812: In central Alabama, United States forces under General Andrew Jackson defeat the Creek at the Battle of Horseshoe Bend.
- 1834 - Andrew Jackson is censured by the U.S. Senate for his actions regarding the U.S. National Bank.
- 1836 - Texas Revolution: Goliad massacre - Antonio López de Santa Anna orders the Mexican army to kill about 400 Texans at Goliad, Texas.
- 1846 - Mexican–American War: Siege of Fort Texas.
- 1851 - First reported case of Europeans seeing Yosemite Valley.
- 1868 - The Lake Ontario Shore Railroad Company is organized in Oswego, New York.
- 1890 - A tornado strikes Louisville, Kentucky, killing 76 and injuring 200.
- 1943 - World War II: Battle of the Komandorski Islands - In the Aleutian Islands the battle begins when United States Navy forces intercept Japanese attempting to reinforce a garrison at Kiska.
- 1945 - World War II: Operation Starvation, the aerial mining of Japan's ports and waterways begins.
- 1964 - The Good Friday earthquake, the most powerful earthquake in U.S. history at a magnitude of 9.2 strikes South Central Alaska, killing 125 people and inflicting massive damage to the city of Anchorage.
- 1969 - Mariner 7 is launched.
- 1977 - Tenerife airport disaster: Two Boeing 747 airliners collide on a foggy runway on Tenerife in the Canary Islands, killing 583 (all 247 on KLM and 335 on PAN AM) and 61 survived on a PAN AM flight.
- 1990 - The United States begins broadcasting TV Martí to Cuba in an effort to bridge the information blackout imposed by the Castro regime.
- 1994 - One of the biggest tornado outbreaks in recent memory hits the Southeastern United States. One tornado slams into a church in Piedmont, Alabama during Palm Sunday services killing 20 and injuring 90.
- 1998 - The Food and Drug Administration approves Viagra for use as a treatment for male impotence, the first pill to be approved for this condition in the United States.
- 2000 - Phillips explosion of 2000 killed 1 and injured 71 in Pasadena, Texas.