Accessing brief history of mankind in space:
Mid-20th century: Mankind races to space, landing on the moon and establishing the first space stations.
Late 20th century: Mankind's interest in space travel dwindles, even if satellites search for extra-terrestial life while satellite density in Earth's orbit increases and private corporations start to dream of space tourism.
Mid-21st century: Mankind's interest in space travel is resurrected by the invention of ion engines and wormhole drives. Long trips can be done in mere hours.
Early 22nd century: Mankind reaches Centauri system and establishes colonies, starting their realistic reach for the stars. The lawless colonies cannot be managed and are abandoned.
Late 22nd century: Colonies are re-established, this time properly and law kept under the banner of the United Space Agency. Nations of Earth start to form larger governments after poor nations start to crumble due to the lack of colonies to keep them running.
Late 23rd century: The United Space Agency is formed into the government of Earth as well as the Colonies. New name: Unified Space Alliance. Rsistance groups rise due to the new government's lack of democracy.
Early 24th century(Now): Civil War begins. Colony worlds unite into the Colony Space Alliance, engaging the USA in frontal assaults. Many CSA worlds become lawless during the war and after the CSA is defeated, are hard to subdue under USA laws. Gunslingers run the towns now.
On the planet called Andros, the gunslingers were at their worst. Towns were either run by oppressive criminals or lawful rangers, but in either case the one making things work were the gunslingers. It was like a re-enactment of the American Old West, but with spaceships and other such additional technologies. Even thought the weapons were still quite primitive and especially in the Colonies the revolvers and rifle designs of old had become quite fashionable lately.