History of the Day for:
April 9
- 1682: The French explorer Robert La Salle reached the Mississippi River.
- 1833: The first publicly supported library was founded in Peterborough, N.H.
- 1865: Confederate Gen. Robert E. Lee and surrendered his army to Union Gen. Ulysses S. Grant at Appomattox Court House in Virginia.
- 1872: Samuel R. Percy patented dried milk.
- 1928: Mae West made her Broadway debut in "Diamond Lil."
- 1912: The Boston Red Sox opened Fenway Park by defeating Harvard, 2-0.
- 1939: Marian Anderson performed a concert at the Lincoln Memorial in Washington after the Daughters of the American Revolution denied her the use of Constitution Hall.
- 1940: World War II: Germany invades Denmark and Norway.
- 1942: American and Philippine defenders on Bataan surrendered to Japanese forces. Nearly 10,000 died following the surrender during the "Bataan Death March."
- 1945: World War II: The German pocket battleship Admiral Scheer is sunk.
- 1945: World War II: The Battle of Königsberg, in East Prussia, ends.
- 1953: Warner Brothers, the first of the major Hollywood studios to introduce 3-D motion pictures, premiered "The House of Wax" in New York City.
- 1959: NASA announced America's first seven astronauts for project Mercury: Scott Carpenter, Gordon Cooper, John Glenn, Virgil "Gus" Grissom, Wally Schirra, Alan Shepard and Donald "Deke" Slayton.
- 1963: Winston Churchill was made an honorary United States citizen.
- 1965: Major-league baseball played its first indoor game when the Astrodome opened in Houston.
- 1984: Actress Shirley MacLaine received her first Academy Award for the film "Terms of Endearment" at the 56th annual Oscars presentation. Other winners included Linda Hunt (Best Supporting Actress for "The Year of Living Dangerously"), Jack Nicholson (Best Supporting Actor for "Terms of Endearment"), Robert Duvall (Best Actor for "Tender Mercies") and "Terms of Endearment" (Best Picture.)
- 1992: A U.S. Federal court found former Panamanian dictator Manuel Noriega guilty of drug trafficking, money laundering and racketeering.
- 1999: Ibrahim Baré Maďnassara, President of Niger, is assassinated.
- 2002: The funeral of Queen Elizabeth, the Queen Mother at Westminster Abbey.
- 2003: 2003 invasion of Iraq: Baghdad falls to American forces.
- 2005: Charles, Prince of Wales marries Camilla Parker Bowles.