Concerning Stories Never Written

I have read Robert Heinlein's post-script to some editions of Revolt In 2100, "Concerning Stories Never Written," for the very first time. Heinlein neatly summarizes the first three volumes of the Future History and the first three unwritten stories, that might have comprised a volume between Vols II and III:

The Man Who Sold The Moon covers the second half of the twentieth century and ends with very early space travel;

The Green Hills Of Earth describes the exploration of the Solar System in the early twenty first century and "...end[s] with the United States a leading power in a systemwide imperialism embracing all the habitable planets";

Revolt In 2100 begins with the US under an isolationist Theocracy;

"The Sound Of His Wings" would have described the rise of the First Prophet;

"Eclipse" would have described Martian and Venerian independence;

"The Stone Pillow" would have described the growth of the anti-Theocratic underground.

(Heinlein does not mention that the contents of Vols I and II overlap.)

He was right that:

space travel might be marginal, subsidized for military reasons, then die out;

anti-scientific televangelization could, maybe in an economic depression, lead to a dictatorship.

This post-script gives a considerable insight into Heinlein and his series. It is an important part of the History and should be included in any future edition.