From the YouTube description:
one of the earliest Star Trek conventions occurred in 1976 at the Northgenn Mall in Denver Colorado in Fall of 1976.
Only 7 years after the series ended, Star Trek already had a very strong cult following in the US and even abroad. There were small fan clubs popping up all over the world, so after awhile it had such momentum that someone began organizing these gatherings into conventions…
At homes, schools, malls, they eventually had to rent large convention halls to accommodate the throngs of devoted ‘trekkies’.
This one had Leonard Nimoy (Spock) and James Doohan (Scotty), so I had to bring my super 8 movie camera to the Mall to film it.
I brought my old pal Terry McCoy as the on-camera reporter to interview the cults and play with the toys.
The Northglenn Mall (The Mall of my adolescence) was only 8 years old at this point so it is fun to have this record of the old Mall before it got torn down 21 years later.