What helped America transform from a war time economy to such a high level of success in post war times?

the treaty of brest-litovsk was a peace treaty signed on 3 march 1918 between the new bolshevik government of russia and the central powers (german empire, austria-hungary, bulgaria, and the ottoman empire), that ended russia's participation in world war i.

it made them more prductive and efficent but with the change of polcies less and les got into the navy

c. the passage of the fifteenth amendment