World War II led to a major advancement in domestic education because the GI bill was introduced, which allowed returning veterans to go to college for free. This greatly increased the education labor force and subsequently GDP. In terms of International Relations, the US left WWII the undisputed leader of the world.
Congress's power to override the President's veto forms a “balance” between the branches on the lawmaking power. ... Congress can override a veto by passing the act by a two-thirds vote in both the House and the Senate. (Usually an act is passed with a simple majority.)