Shortly after 8 p. m. on October 30th, 1938, the voice of a panicked radio announcer broke in with a news bulletin reporting strange explosions taking place on the planet Mars, followed minutes later by a report that Martians had landed in the tiny town of Grovers Mill, New Jersey. It turned out to be H. G. Wells' classic 'The War of the Worlds', performed by 23-year-old Orson Welles. Although most listeners understood that the program was a radio drama, the next day's headlines reported that thousands of others plunged into panic, convinced that America was under a deadly Martian attack. 75 years after the original radio broadcast, 'American Experience' examines the elements that came together to create one of the biggest mass hysteria events in U. S. history.