They did save the Union. It is now up to us to preserve it.
But the name of union definitely applies.
"That the United States form, for many, and for most important purposes, a single nation, has not yet been denied. In war, we are one people. In making peace, we are one people. In all commercial regulations, we are one and the same people. In many other respects, the American people are one; and the government which is alone capable of controlling and managing their interests in all these respects, is the government of the Union. It is their government and in that character, they have no other. America has chosen to be, in many respects, and in many purposes, a nation; and for all these purposes, her government is complete; to all these objects it is competent. The people have declared that in the exercise of all powers given for these objects, it is supreme. It can, then, in effecting these objects, legitimately control all individuals or governments within the American territory.
The constitution and laws of a state, so far as they are repugnant to the constitution and laws of of the United States are absolutely void. These states are constituent parts of the United States; they are members of one great empire--for some purposes sovereign, for some purposes subordinate."
--Chief Justice John Marshall, writing the majority opinion, Cohens v. Virginia 1821
Walt
They tore it down in an attempt to hold it together by exerting forces contrary to that union's nature and in violation of its founding principles.