2001: Auto racing star Dale Earnhardt Sr. dies in a crash at the Daytona 500; he was 49.

1546: Martin Luther, leader of the Protestant Reformation in Germany, dies in Eisleben.

1861: Jefferson Davis is sworn in as provisional president of the Confederate States of America in Montgomery, Alabama.

1930: Photographic evidence of Pluto (now designated a “dwarf planet”) is discovered by Clyde W. Tombaugh at Lowell Observatory in Flagstaff, Arizona.

1970: The “Chicago Seven” defendants are found not guilty of conspiring to incite riots at the 1968 Democratic national convention; five are convicted of violating the Anti-Riot Act of 1968. (Those convictions would be later reversed).

1972: The California Supreme Court strikes down the state’s death penalty.

1977: The space shuttle prototype Enterprise, sitting atop a Boeing 747, goes on its debut “flight” above Edwards Air Force Base in California.

1983: In what became known as the “Wah Mee Massacre,” 13 people are shot to death at a gambling club in Seattle’s Chinatown. (Two men would be convicted of the killings and are serving life sentences; a third would be found guilty of robbery and assault.)

1988: Anthony M. Kennedy is sworn in as an associate justice of the U.S. Supreme Court.

1997: Astronauts on the space shuttle Discovery complete their tune-up of the Hubble Space Telescope after 33 hours of spacewalking; the Hubble is then released using the shuttle’s crane.

2014: Megan Rice, an 84-year-old nun, is sentenced in Knoxville, Tennessee, to nearly three years in prison for breaking into a nuclear weapons complex and defacing a bunker holding bomb-grade uranium, a demonstration that exposes serious security flaws at the Y-12 National Security Complex in Oak Ridge. (Two other activists receive sentences of just over five years.)

2018: “Black Panther,” the Marvel superhero film from the Walt Disney Co., exceeds expectations to take in $192 million during its debut weekend in U.S. and Canadian theaters.