Up until the last few months, when states have started to assert their rights through such actions as resolutions and the formation of the Patrick Henry Caucus, I am convinced that the Tenth Amendment has long been the most widely ignored of our Bill of Rights amendments.
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
Few people are even alive today who can remember a time when the Federal Government was not grossly trampling the rights of states. Although such overreaching has been going on to some degree for virtually our entire history it seems that especially since the passage of the 16th and 17th amendments the Federal government has been treating the states as vassals rather than sovereign territories.
This amendment is the second half of the 9th Amendment. The Constitution recognizes essentially three entities: the people, the states, and the federal government. The 9th and 10th Amendments were supposed to ensure that the federal government was kept in its place and restricted to only its enumerated powers. As you state, the 10th Amendment fell apart after the Civil War.
In his book “Ain’t My Country”, Bill Kauffman relates state vassalage to progressive embroilment of America in foreign empire. It’s not possible, he says, to “bring Democracy” to other nations without first regimenting our own society.
The annexation of Hawaii, the subduing of the Phillipines, and the Spanish American war started the ball rolling toward the near death of the 9th and 10th Amendments. World Wars I & II, Korea, Vietnam, and Iraq I and II have put most of the rest of the nails in that coffin.
While I believe that state vassalage and an empire building mentality are both serious problems related to our expansion of federal power I don’t believe there is a cause/effect relationship between the two (I would guess the relationship is more symbiotic). I guess I’d need to read Kauffman’s book to better understand what kind of relationship he sees between those two problems.