The Union should have been one of 13 sovereign states, without giving so much power to the behemoth the federal government has no become.
In reality, though, much of what it HAS become is plainly unconstitutional, yet the highest court in the land will not declare it that, as they are as political as the other two branches, and in the long their highest calling is their own existence, rather than that document I took an oath to.
You and I could kill a few evenings and bottles of scotch over this one.
IMHO, the Civil War resolved the intent of state separation and the Tenth Amendment. The war put the fed directly into state government and allowed the fed to dictate to states. As much as slavery was the reason behind the Civil War, the issue of states rights fit into it as well. Up until then states believed they were autonomous and independent. Not so, in the end.