Published as the newsstand distribution system for comics began to break down, Kirby foresaw a day when comics would need to find alternate, more legitimate venues for sale. Toward this end, Kirby envisioned a finite series that would be serialized and collected in one tome after the series had concluded.
The three original titles comprising the "Fourth World" were The Forever People, Mister Miracle and New Gods. The pre-existing title Superman's Pal Jimmy Olsen was used by Kirby to introduce the Fourth World concept and characters.
To check out the full retrospective of Kirby's Fourth World, just click on the image below.