August 20 - Low Carb Diabetic

Czech youngsters holding Czechoslovakian flags stand atop of an overturned truck as other Prague residents surround Soviet tanks in downtown Prague on Aug. 21, 1968, as a Soviet-led invasion by the Warsaw Pact armies crushed the so-called Prague Spring reform in former Czechoslovakia 30 years ago. (AP Photo/Libor Hajsky/CTK)

By THE ASSOCIATED PRESS

Today in history:

On Aug. 20, 1968, the Soviet Union and other Warsaw Pact nations invaded Czechoslovakia to crush the “Prague Spring” liberalization movement.

Also on this date:

In 1858, Charles Darwin’s theory of evolution was first published, in the “Journal of the Proceedings of the Linnean Society”.

This is a photo of Horace Greeley in 1868. Greeley was the editor of the weekly "New Yorker" in 1834 and began The New York Tribune 1841, which was later merged with the New York Herald to become The New York Herald Tribune. (AP Photo) — This is a photo of Horace Greeley in 1868. Greeley was the editor of the weekly “New Yorker” in 1834 and began The New York Tribune 1841, which was later merged with the New York Herald to become The New York Herald Tribune. (AP Photo)

In 1862, the New York Tribune published an open letter by editor Horace Greeley calling on President Abraham Lincoln to take more aggressive measures to free enslaved people and end the South’s rebellion.

In 1866, President Andrew Johnson declared the official end of the Civil War.

In 1882, Tchaikovsky’s “1812 Overture” had its premiere in Moscow.

In 1910, a series of wildfires swept through parts of Idaho, Montana and Washington, killing at least 85 people and burning some 3 million acres.

In 1920, the American Professional Football Conference was established by representatives of four professional football teams; two years later, with 18 teams, it would be renamed the National Football League.

A Mexican policeman holds the short- handled pickax used by Ramon Mercader when he attacked and fatally wounded exiled Russian revolutionary Leon Trotsky at his closely guarded home in Mexico City, Aug. 20, 1940. Mercader, aka Jacques Mornard and Frank Jackson, was considered a "friend of the family," by Trotsky. Before he died of his wounds, Trotsky said that his death was ordered by Josef Stalin. (AP Photo) — A Mexican policeman holds the short- handled pickax used by Ramon Mercader when he attacked and fatally wounded exiled Russian revolutionary Leon Trotsky at his closely guarded home in Mexico City, Aug. 20, 1940. Mercader, aka Jacques Mornard and Frank Jackson, was considered a “friend of the family,” by Trotsky. Before he died of his wounds, Trotsky said that his death was ordered by Josef Stalin. (AP Photo)

In 1940, exiled Communist revolutionary Leon Trotsky was attacked in Coyoacan, Mexico by assassin Ramon Mercader. (Trotsky died the next day.)

In 1964, President Lyndon B. Johnson signed into law the Economic Opportunity Act, a nearly $1 billion anti-poverty measure.

An unidentified Edmond, Oklahoma, postal worker who survived the massacre of 14 colleagues is comforted by his wife and daughter, Aug. 20, 1986, Edmond, Ok. Patrick Sherill, a 44-year-old mail carrier afraid of losing his job, gunned down fellow workers and then killed himself. (AP Photo/David Longstreath)

In 1986, postal employee Patrick Henry Sherrill went on a deadly rampage at a post office in Edmond, Oklahoma, shooting 14 fellow workers to death before killing himself.

In 1989, 51 people died when the pleasure boat Marchioness sank in the River Thames in London after being struck by a dredger.

FILE - In this April 10, 2013, file photo, former Secretary of State Condoleezza Rice watches the par-3 competition before the Masters golf tournament in Augusta, Ga. (AP Photo/Charlie Riedel, File)

In 2012, after 80 years in existence, Georgia’s Augusta National golf club (home to the Masters Tournament) invited former Secretary of State Condoleezza Rice and South Carolina financier Darla Moore to become its first female members; both accepted.