Yes, the centralized empire was made manifest by the war. Was there ever a voluntary, decentralized union, however, that was not already an empire abuilding, a waxing empire? I say again that the Union itself was the formation of an empire in 1787. The war won by the North in 1865 confirmed this empire and led to its further realization in the Indian wars and other ways. It was a quantum jump. But before 1861, can we not find in the legislative and judicial and executive actions of the federal government ample evidence that this government was not a weak and ineffective thing, but a centralizing force that was already going beyond the Constitution? See, for example, the article by Jim Davies, "1789." Consider the incorporation and formation of the First and Second National Banks. Consider Marshall's interpretation of the necessary and proper clause.