This is truly fascinating. Richard Portnoy shot the following footage in August of 1975 at the Star Trek Chicago '75 Convention with an 8mm camera. It was the first time the entire cast of Star Trek had reunited in front of fans. Between 15,000 and 16,000 were on hand for the convention, held from August 22nd to August 24th. Portnoy provides narration over the silent footage, which runs roughly three minutes.