Most of the Founding Fathers, including Washington, Jefferson, Madison, slave owners, looked forward to the end of slavery. See the Wallbuilders on The Founding Fathers and Slavery.
To say that the Union Civil War effort was unconstitutional is obviously incorrect. One of the purposes of the Constitution is "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions"
Interesting that you should point out that one of the purposes of the Constitution was to support Militias. Does this mean that the interpretation that heavy arms should be reserved for “a well regulated militia” and that lighter arms are suited for individual hunters and home owners is the correct one?