Watch videos about Hugh Hefner and how he turned 'Playboy' magazine into a worldwide empire that played a role in the sexual revolution of the 1960s.

Watch short videos about Founding Fathers of the U.S. including  George Washington, Alexander Hamilton, Thomas Jefferson, Benjamin Franklin, John Adams, Samuel Adams, Paul Revere and John Hancock.

Discover the early life of Kate Middleton and how she met Prince William at the University of St. Andrews. Learn about their courtship, their famous royal wedding in 2011, and how she's adjusted to palace life and expanding family.