Millions of people have spent the last two decades spouting alternative ideas about what may have happened on September 11, 2001, but are any of these 9/11 conspiracy theories even rooted in truth?

He participated in an infamous massacre of Union soldiers, but when he got to write his own story, Jesse James cast himself as the Robin Hood of the Wild West.

Inside the Aktion T4 program, the little-known euthanasia initiative that killed as many as 300,000 disabled people as the Nazis swept across Europe.

Some are convinced the government uses Area 51 to dissect aliens and study flying saucers. In truth, the classified site has been used to build spy planes — and dump toxic waste.

The Ustaše brutalized and massacred upwards of 300,000 Serbians, 30,000 Jews, and 29,000 Romani people throughout their four-year reign of terror in Croatia.

After 10 years behind bars, John Dillinger went on a year-long bank-robbing spree that captured America's imagination.

These facts about the Leaning Tower of Pisa reveal everything there is to know about the world's most famous architectural mistake.

From New York City's most feared creature to an insect that can kill you with its feces, these house bugs are beyond horrifying.

What really happened to the Führer? These Hitler death conspiracy theories, from the plausible to the outlandish, claim to have the answers.

From his love of cigars to his actual lover, no idea was a bad idea when it came to Fidel Castro assassination attempts.

Despite what you may think, Mormon history is full of scandal, violence, and lies.