Muhammad Ali took a controversial stand on this day in 1967. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Ferdinand Magellan's historic journey came to an end on this day in 1521. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Polio vaccine trials began in Virginia on this day in 1954. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The Hubble Space Telescope began its extraordinary journey on this day in 1990. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The world’s largest library got its start on this day in 1800. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hank Aaron hit his first Major League homer on this day in 1954. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The first Earth Day was celebrated on this day in 1970. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The musician Prince died on this day in 2016. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Tragedy unfolded at a Colorado high school on this day in 1999. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Terrorists attacked Oklahoma City on this day in 1995. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The biggest earthquake in U.S. history hit San Francisco on this day in 1906. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The U.S. bid farewell to its oldest founding father on this day in 1790. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A massive explosion rocked a Texas city on this day in 1947. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Jackie Robinson played his first game for the Dodgers on this day in 1947. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Abraham President Lincoln was assassinated on this day in 1865. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Golfer Tiger Woods made history on this day in 1997. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The first shots of the American Civil War were fired on this day in 1861. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Apollo 13 launched from Cape Canaveral on this day in 1970. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Ping pong played a role in U.S. foreign policy on this day in 1971. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The American Civil War came to an end on this day in 1865. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A key New Deal project was passed on this day in 1935. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The internet was born on this day in 1969. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The U.S. entered one of history’s deadliest conflicts on this day in 1917. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A controversial Cold War execution was carried out on this day in 1951. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Martin Luther King, Jr. was assassinated on this day in 1968. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A notorious outlaw met his end on this day in 1882. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A Montana woman made history on this day in 1917. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Why do we celebrate April Fool's Day? Learn more about your ad choices. Visit podcastchoices.com/adchoices

The Dalai Lama left Tibet for India on this day in 1959. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The US paid just two cents an acre for some prime real estate on this day in 1867. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The "Mad Bomber" struck New York City on this day in 1951. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Three Mile Island becomes a household name on this day in 1979. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Washington, D.C.'s first cherry trees were planted on this day in 1912. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A new vaccine that saved thousands from a crippling disease is announced on this day in 1953. Learn more about your ad choices. Visit podcastchoices.com/adchoices

U.S. Customs agents act to protect Americans from a poem on this day in 1955. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The Exxon Valdez ran aground in Alaska’s Prince William Sound on this day in history. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A popular English phrase makes its national debut thanks to a Boston newspaper. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The ERA was passed by Congress on this day 1972, but never became law. Find out why not. Learn more about your ad choices. Visit podcastchoices.com/adchoices

TV’s most famous cliffhanger left American wondering who shot the Texas oilman they loved to hate. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A novel that helped start a war was published on this day in 1852. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Las Vegas gambled on its future on this day in 1931. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Parisians welcomed a new way to get around the city on this day in history. Learn more about your ad choices. Visit podcastchoices.com/adchoices

What do 33 million Americans have in common? Find out. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A tumultuous day on Wall Street ends in the collapse of a historic company on this day in 2008. Learn more about your ad choices. Visit podcastchoices.com/adchoices

What are the ides of March, and should you really beware? Learn more about your ad choices. Visit podcastchoices.com/adchoices

A top-ten list no one wants to make debuted on this day in 1950. Learn more about your ad choices. Visit podcastchoices.com/adchoices

The U.S. Army launches the K-9 Corps on this day in 1942. Learn more about your ad choices. Visit podcastchoices.com/adchoices

A much-publicized manhunt comes to an end on this day in 2003. Learn more about your ad choices. Visit podcastchoices.com/adchoices