Zenna Henderson's "The People" short stories were published in a variety of anthologies, and were only collated through the efforts of the 'New England Science Fiction Association' who obtained the rights and published them as "Ingathering: The complete People stories" in 1995.
This movie marks the reunion between Kim Darby and William Shatner since they previously starred together in Star Trek (1966). Episode: Miri (1966).