Bethesda has released a timeline for Starfield, providing you with information on the goings on in the universe before you step into the story.
It covers the years 2050 through 2330 from when humans first arrived on Mars to where things kick off with your arrival in the game.
It also discusses the war between the factions of the United Colonies and the Freestar Collective that started in 2196 and ended in 2216 with the signing of the Treaty of Narion. But the treaty is a bit shaky, and fighting breaks out again with The Colony War in 2307.