Approximately 40% of the U.S. paper currency in circulation was counterfeit by the end of the Civil War.
47
The exact cause of death and burial site of Genghis Khan is unknown, because all of the 2000 funeral guests and 800 soldiers were killed in order to preserve the secret.
16
No one knows who designed the first American Flag.
45
There’s a Swedish power metal band called “Sabaton” who teach history through their music, including an album devoted to teaching about World War Two.
30
No one knows how many people died during the sinking of the Titanic.
11