To prevent one branch from taking too much power, the constitutional convention set up a system of:
checks and balances
executive branches
national courts

A development from 1861 to 1865 not directly mentioned in the excerpt to support McPherson historical argument interpretation of the civil war is on the question passed on whether to concentrate on war that killed over a million people or to question whether the war was a necessity. The excerpt supports McPherson's argument that the war was in three forms, first through the mobilization of human and material resources by both sides, secondly, it ended with negotiated peace where victory ranged on one side but destroyed the economy and social systems of the losers. It led to the creation of a new Nation.