History Shorts: Why We Pay Income Taxes

The White House is meant to reflect its occupant, and when a new president comes to town, things have to be changed very quickly. But what goes into the peaceful transfer of power? And how do workers turn the White House over in the blink of an eye?

No mission is too difficult for Delta Force, an elite unit of highly skilled warriors called upon for the most dangerous operations and critical moments.

From women's suffrage to the fight for racial justice, learn about some of the largest protest movements in American history.

The Defense Advanced Research Projects Agency (DARPA) sets out on an initiative to develop nonsurgical neuro technology.