THIS DAY IN HISTORY ― AUGUST 21

August 21 is the 233rd day of the year (234th in leap years) in the Gregorian calendar. There are 132 days remaining until the end of the year. This date is slightly more likely to fall on a Tuesday, Friday or Sunday (58 in 400 years each) than on Wednesday or Thursday (57), and slightly less likely to occur on a Monday or Saturday (56).

NATIONAL SPUMONI DAY 

1680 – Pueblo Indians capture Santa Fe from the Spanish during the Pueblo Revolt.

1778 – American Revolutionary War: British forces begin besieging the French outpost at Pondichéry.

1831 – Nat Turner leads black slaves and free blacks in a rebellion in Southampton County, Virginia, which will claim the lives of 55-65 whites.

1863 – Lawrence, Kansas is destroyed by Confederate guerrillas Quantrill's Raiders in the Lawrence Massacre.

1883 – An F5 tornado strikes Rochester, Minnesota, leading to the creation of the Mayo Clinic.

1888 – The first successful adding machine in the United States is patented by William Seward Burroughs.

1911 – The Mona Lisa is stolen by a Louvre employee.

1914 – World War I: The Battle of Charleroi, a successful German attack across the River Sambre which pre-empted a French offensive in the same area.

1942 – World War II: The Guadalcanal Campaign ― American forces defeat an attack by Imperial Japanese Army soldiers in the Battle of the Tenaru.

1945 – Physicist Harry Daghlian is fatally irradiated in a criticality accident during an experiment with the Demon core at Los Alamos National Laboratory.

1957 – The Soviet Union successfully conducts a long-range test flight of the R-7 Semyorka, the first intercontinental ballistic missile.

1959 – United States President Dwight D. Eisenhower signs an executive order proclaiming Hawaii the 50th state of the union. Hawaii's admission is currently commemorated by Hawaii Admission Day

1968 – In the Vietnam War, James Anderson, Jr. posthumously receives the first Medal of Honor to be awarded to an African-American U.S. Marine.

1982 – Lebanese Civil War: The first troops of a multinational force lands in Beirut to oversee the Palestine Liberation Organization's withdrawal from Lebanon.

1986 – Carbon dioxide gas erupts from volcanic Lake Nyos in Cameroon, killing up to 1,800 people within a 20-kilometer range.

1988 – The 6.9 Mw Nepal earthquake shakes the Nepal–India border with a maximum Mercalli intensity of VIII (Severe), leaving 709–1,450 people killed and thousands injured.

1992 – Ruby Ridge Standoff in Idaho between Randy Weaver, his family, his friend Kevin Harris, and agents of the United States Marshals Service (USMS) and Federal Bureau of Investigation (FBI).

1993 – NASA loses contact with the Mars Observer spacecraft.

2013 – Hundreds of people are reported killed by chemical attacks in the Ghouta region of Syria.

TODAY'S BIRTHS

1754 – William Murdoch, Scottish engineer and inventor, created gas lighting (d. 1839)

1869 – William Henry Ogilvie, Scottish-Australian poet and author (d. 1963)

1904 – Count Basie, American pianist, composer, and bandleader (d. 1984)

1906 – Friz Freleng, American animator, director, and producer (d. 1995)

1924 – Jack Buck, American sportscaster (d. 2002)

1943 – Lucius Shepard, American author and critic (d. 2014)

From Wikipedia and Google (images), ex as noted.