On February 18, 1885, Mark Twain publishes his famous—and famously controversial—novel The Adventures of Huckleberry Finn in the U.S.

Pluto, once believed to be the ninth planet, is discovered at the Lowell Observatory in Flagstaff, Arizona, by astronomer Clyde W. Tombaugh.

On February 18, 2001, Dale Earnhardt Sr., considered one of the greatest drivers in National Association for Stock Car Auto Racing (NASCAR) history, dies at the age of 49 in a last-lap crash at the 43rd Daytona 500 in Daytona Beach, Florida. Earnhardt was driving his famous black No. 3 Chevrolet and vying for third place when he collided with another car, then crashed into a wall. After being cut from his car, Earnhardt, whose tough, aggressive driving style earned him the nickname “The Intimidator,” was taken to a hospital, where he was pronounced dead of head injuries.

On February 18, 2010, a relatively obscure website called WikiLeaks publishes a leaked diplomatic cable detailing discussions between American diplomats and Icelandic government officials. The leak of "Reikjavik13" barely registered with the public, but it was the first of what turned out to be nearly 750,000 sensitive documents sent to WikiLeaks by Chelsea Manning. Manning is now considered one of the most prolific and significant whistleblowers in American history, as her leaks shed light on atrocities committed by American armed forces, painted a far grimmer picture of the wars in Iraq and Afghanistan and greatly embarrassed the United States’ diplomatic establishment.