Chinese Language Day – This day celebrates the use of Chinese language in the United Nations, as one of the six official languages.
Volunteer Recognition Day – This day is dedicated to recognizing and thanking volunteers for their contributions and services in their communities.
Lima Bean Respect Day – This unofficial holiday promotes the consumption and appreciation of the lima bean.
Look-Alike Day – This day is all about celebrating the similarities between people and having fun by dressing up as someone who looks similar to you or someone else.
1303: The Sapienza University of Rome is founded.
1653: Oliver Cromwell dissolves the Rump Parliament in England and replaces it with the Barebones Parliament.
1775: The Siege of Boston begins during the American Revolutionary War.
1792: France declares war on Austria, marking the beginning of the French Revolutionary Wars.
1836: The Battle of San Jacinto takes place in present-day Texas, where the Texan army led by Sam Houston defeats the Mexican army led by General Antonio López de Santa Anna, ending the Texas Revolution.
1861: Robert E. Lee resigns from the United States Army, later becoming a general for the Confederate States of America during the American Civil War.
1902: Pierre and Marie Curie refine radium chloride to produce a sample of radium that is a hundred times more radioactive than pure uranium.
1912: Fenway Park, home of the Boston Red Sox, opens its doors for the first time.
1945: Soviet forces capture Berlin during World War II.
1961: Failure of the Bay of Pigs Invasion, a CIA-sponsored attempt to overthrow the government of Cuban leader Fidel Castro.
1972: Apollo 16, the fifth manned mission to land on the Moon, is launched by NASA.
1999: The Columbine High School massacre occurs in Colorado, United States, where two students kill 13 people before committing suicide.
2010: An explosion on the Deepwater Horizon oil rig in the Gulf of Mexico leads to the largest offshore oil spill in United States history.