As a point of fact, they didn't. The war destroyed the "Union" as it was known before the war and replaced it with a centralized empire.
...which went on to save the World, twice, and provide for its citizens (including you and me) and the Free World a higher degree of freedom and material prosperity than humanity has ever known.
Call me a proud Citizen
I know you would call prob'ly call me a "Dupe", 'mongst other things...