April 1 is the 91st day of the year (92nd in leap years) in the Gregorian calendar; 274 days remain until the end of the year.
1515 Portuguese fleet under Afonso de Albuquerque capture the Persian fortress of Hormuz, renaming it the Fort of Our Lady of the Conception
• 1693 Cotton Mather's four-day-old son dies, and witchcraft is blamed 1863 US Congress passes the first wartime conscription law, calling for the registration of all 20 to 45-year-old males
• 1865Battleat Fort Blakeley, Alabama, between Major General Edward Canby's Union forces and Brigadier General St. John R. Liddell 1938 World heavyweight boxing champion Joe Louis KOs Harry Thomas in fifth round of their title bout in Chicago 1941 Nazis forbid Jewish access to cafés 1945 Battle of Okinawa: US ground forces invade Okinawa in the largest amphibious assault of the Pacific theatre