And James Blish

As an addendum to the previous post, James Blish comes between Heinlein and Anderson, both chronologically and conceptually, similar to Anderson but with a much smaller output. Blish is the only other sf author that I know of with more than one future history although fewer than Anderson. Anderson's future histories, to summarize not for the first time, cover:

a Heinleinian Time Chart

social change

post-nuclear Earth

asteroid colonization

extra-solar colonization

interstellar trade

human-AI interaction

post-human AI

- which makes them sound as if they could have been sections of a single series.

Blish's future histories cover:

flying cities

Adapted Men

Einstein's successor, Haertel, remembered in branching timelines

In one of those branching timelines, the novel, The Quincunx of Time, incorporates messages from future periods described in "A Style in Treason" and Midsummer Century, thus uniting these three works into a miniature future history. In Quincunx, an organization called the Service must protect future events just as Anderson's Patrol protects past events and Heinlein's temporal bureau operates in an immutable timeline with circular causality. These successors of Wells seem to encompass every possibility.