History's Mysteries examines the controversy over who was the first responsible for powered flight. A consensus of historians credit the Wright Brothers with this accomplishment, but some believe that others including a German immigrant named Gustave Whitehead were able to achieve fight several years before the historic 1903 flight at Kitty Hawk. It also looks at a controversy between the Wright Brothers and the Smithsonian.
 

For nearly 50 years, what goes on inside these buildings has been known to only a select few. But now, for only the second time, the National Security Agency is opening doors that have been sealed tight.