Orcas have been observed teaching their offspring specific hunting techniques — culture transmitted across generations.

The fastest Olympic swim races are completed in under 25 seconds.

The 16th Amendment authorized a federal income tax.

Jim Thorpe won the pentathlon and decathlon at the 1912 Olympics — King Gustav V of Sweden called him 'the world's greatest athlete.'

Abraham Lincoln was a licensed bartender and co-owned a tavern before entering politics.

In 2000, a massive fireworks accident damaged part of a Dutch city.

Extreme sports athlete Travis Pastrana became the first person to land a double backflip on a motorcycle at X Games 2006.

In 1904, an Olympic marathon included bizarre obstacles and poor organization.

The Olympic rings represent the five continents of the world — but no particular ring is tied to a specific continent.