• 1006: The brightest supernova in recorded history is observed 
• 1789: George Washington is inaugurated as the first President of the United States 
• 1798: The Department of the Navy established by the U.S. second President, John Adams 
• 1803: The United States more than doubles its size through the Louisiana Purchase 
• 1808: First practical typewriter finished by Italian Pellegrini Turri 
• 1812: Louisiana becomes the 18th state 
• 1900: Hawaii becomes a U.S. territory 
• 1900: Train engineer Casey Jones is killed while trying to save the Cannonball Express as it highballed through Vaughn, MS 
• 1939: Lou Gehrig plays his last game with the New York Yankees 
• 1947: Boulder Dam reverts to its original name in honor of Herbert Hoover 
• 1948: Organization of American States (OAS) charter signed in Bogota, Colombia 
• 1955: Scientists announce the discovery of element 101, Mendelevium 
• 1973: President Nixon announces that top White House aides H.R. Haldeman and John Ehrlichman, along with Attorney General Richard Kleindienst and White House counsel John Dean, have resigned amidst the controversies surrounding the investigation of the Watergate break-in 
• 1975: U.S. forces evacuate from Vietnam - Saigon surrenders 
• 2003: Mahmoud Abbas took office as the first Palestinian prime minister.  
• 2003: The U.S. Navy withdrew from its disputed Vieques bombing range in Puerto Rico.
•   2007: A British judge sentenced five al-Qaida-linked men, all British citizens, to life in prison for plotting to attack London targets, including a nightclub, power plants and shopping mall, with bombs.

BOR ON THIS DAY — April 30th