More Of A Future History Than We Might Think

Poul Anderson, New America, "The Queen of Air and Darkness."

No dates are given in Poul Anderson's Rustum History but we do know that immense periods of time elapse:

Atomic Wars
the establishment of a World Federation
the North American Rebellion
a colony on Venus, later abandoned
slower than light interstellar exploration
the Constitutionalists' twenty light year journey to Rustum
a fourth generation growing up on Rustum by the end of the eighth installment

Later:

Confucianist colonists to arrive on Rustum fifty years later
colonization of extra-solar planets further away
specifically, a seventy five light year journey to colonize Roland
generations building a city and a town on Roland
laser communication between planets like Rustum, Roland and Boewulf
the launching of interstellar ships by the older colonies
loss of communication with Earth

How long is all that going to take?

A few sentences are enough to sketch in a future historical background. In certain timelines, is FTL impossible or just never discovered? I think that the author assumes its impossibility and explores the consequences of that. In Heinlein's Future History, Anderson's Psychotechnic History and Niven's Known Space History, a period of STL interstellar travel is followed by a period of FTL which makes sense and which also explains why I chose that image for this post.