Colonizing Mars

In Robert Heinlein's Future History, Earthmen colonize the Moon, Mars and Venus and, in one of his earlier Scribner Juveniles that are closely connected to the Future History, Ganymede also is terraformed and colonized.

In Poul Anderson's Psychotechnic History, these same planets are colonized.

In Larry Niven's Known Space future history, Earthmen, knowing that Venus is uninhabitable and preferring to avoid deep gravity wells, colonize and exploit the asteroids so that before long the Belt needs a Political Section to deal with the UN Earth-Moon government.

In Anderson's Tales Of The Flying Mountains, gravity control makes it possible to terraform and colonize the asteroids.

In Anderson's The Fleet Of Stars:

the Moon is colonized as "...a site for solar energy collectors and a staging area for interplanetary operations..." (5, p. 53);

wealth is mined from asteroids and comets;

Mars is colonized because -

the volcanoes, water and atmosphere of the early Mars had concentrated valuable materials;

low gravity and proximity made it easy for colonists to supply asteroidal workers with food, goods etc;

life support does not require Lunar-style domes or excavations - airtight buildings suffice;

metamorphic plants can grow on the surface;

both Terrans and Lunarians can reproduce in Martian gravity.

The Republic of Mars becomes a nation that endures even when the asteroids are no longer being mined.