Questions composed of pure conjecture serve no purpose.
If the South had won the war (or, Heaven forbid, the Constitution was abided by and the right to leave the compact was acknowledged), perhaps Americans would still be Citizens of one of these united States instead of 'U.S. citizens'.
U.S. v. Anthony 24 Fed. 829 (1873)
"The term resident and citizen of the United States is distinguished from a Citizen of one of the several states, in that the former is a special class of citizen created by Congress."
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The Founders carefully bound the federal power so it could operate in only exclusive and enumerated areas. Under the auspices of freeing the slaves, the Union released those bonds.
"The constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government - lest it come to dominate our lives and interests."
Patrick Henry
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What's the term FReepers use to refer to those who unknowingly assist others to achieve a hidden agenda?
'Useful idiot', I believe.
Perhaps not.
"The unity of government which constitutes you one people is also now dear to you. It is justly so, for it is a main pillar in the edifice of your real independence, the support of your tranquility at home, your peace abroad; of your safety; of your prosperity; of that very liberty which you so highly prize. But as it is easy to foresee that, from different causes and from different quarters, much pains will be taken, many artifices employed to weaken in your minds the conviction of this truth; as this is the point in your political fortress against which the batteries of internal and external enemies will be most constantly and actively (though often covertly and insidiously) directed, it is of infinite moment that you should properly estimate the immense value of your national union to your collective and individual happiness; that you should cherish a cordial, habitual, and immovable attachment to it; accustoming yourselves to think and speak of it as of the palladium of your political safety and prosperity; watching for its preservation with jealous anxiety; discountenancing whatever may suggest even a suspicion that it can in any event be abandoned; and indignantly frowning upon the first dawning of every attempt to alienate any portion of our country from the rest, or to enfeeble the sacred ties which now link together the various parts.
For this you have every inducement of sympathy and interest. Citizens, by birth or choice, of a common country, that country has a right to concentrate your affections. The name of American, which belongs to you in your national capacity, must always exalt the just pride of patriotism more than any appellation derived from local discriminations. With slight shades of difference, you have the same religion, manners, habits, and political principles. You have in a common cause fought and triumphed together; the independence and liberty you possess are the work of joint counsels, and joint efforts of common dangers, sufferings, and successes." -- George Washinton, 1796.