On October 20, 1938, Orson Welles’ radio play War of the Worlds went out over the airwaves, amusing most, rattling others to their core. 

On Halloween morning, 1938, Orson Welles awoke to find himself the most talked about man in America. The night before, Welles and his Mercury Theatre on the Air had performed a radio adaptation of H.G. Wells’s The War of the Worlds, converting the 40-year-old novel into fake news bulletins describing a Martian invasion of New Jersey. Some listeners mistook those bulletins for the real thing, and their anxious phone calls to police, newspaper offices, and radio stations convinced many journalists that the show had caused nationwide hysteria. By the next morning, the 23-year-old Welles’s face and name were on the front pages of newspapers coast-to-coast, along with headlines about the mass panic his CBS broadcast had allegedly inspired.
The Infamous “War of the Worlds” Radio Broadcast Was a Magnificent Fluke | Smithsonian

Celebrate the Century – 1940’s – Orson Welles
Released in 1999 by USPS as part of their
Celebrate the Century series
Designed by Carl Herrman
Illustrations by Howard Koslow

“I had conceived the idea of doing a radio broadcast in such a manner that a crisis would actually seem to be happening,” he said, “and would be broadcast in such a dramatized form as to appear to be a real event taking place at that time, rather than a mere radio play.” 
Orson Welles, 1960 from a court deposition
The Infamous “War of the Worlds” Radio Broadcast Was a Magnificent Fluke | Smithsonian

The War of the Worlds
Released by Royal Mail in 1995
From the Science Fiction. Novels by H.G. Wells series
Designer: Siobhan Keaney

The War of the Worlds, by H.G. Wells
Released 1998 by San Marino
From the Science Fiction Novels series
Designer: Franco Filanci