“Before the Declaration of Independence, “subject” and “denizen” 2 were the terms most frequently used in’the United States in connections where “citizen” would now be the proper word. This was the natural usage in what then were British colonies, endowed with all the trimmings of the British legal order. Even after the Declaration of Independence, some states enacted constitutions designating as “subjects” the status which others identified by the term “inhabitants,” while still others used “citizens” and “subjects” indiscriminately.”

“Subjects” of the United States of America were referred to in the treaties signed by the Continental Congress with France (February 6, 1778) 4 and the Netherlands (October 8, 1782).1 appears as early as 1777 in the Articles of Confederation,” the use of “subject” as a synonym did not become obsolete before the enactment of the Federal Constitution (1787), which referred to citizens exclusively, both in relation to the United States and to the several states.”

“This change of usage resulted from an emerging political philosophy which abhorred any tinge of colonialism. The term “subject” was brushed aside as a leftover from the feudal law, where it referred to the vassals of a lord, bound by the duty of allegiance to respect him as their master.10 However, one of the ingredients of the feudal theory of subjection survived: the concept of allegiance still forms a tautological part ” of our statutory definition of nationality.” 

“The term “citizen” supplanted “subject” in this country and others, although not in Great Britain,” by a process of lexicographic delineation. Even in the period immediately before the American Revolution, there was no such difference in connotation between “subject” and “citizen” as would predicate reserving the status of “citizen” to the people of a republic and “subject” to those under the sovereignty of a monarch.”

Source: “SUBJECT,” “CITIZEN,” “NATIONAL,” AND “PERMANENT ALLEGIANCE” MAXIMILIAN KOESSLER 

“The foundation of a republic is the virtue of its citizens. They are at once sovereigns and subjects. As the foundation is undermined, the structure is weakened. When it is destroyed the fabric must fall. Such is the voice of universal history. * * * The theory of our government is, that all public stations are trusts, and that those clothed with them are to be animated in the discharge of their duties solely by considerations of right, justice and the public good. They are never to descend to a lower plane. But there is a correlative duty resting upon the citizen. In his intercourse with those in authority, whether executive or legislative, touching the performance of their functions, he is bound to exhibit truth, frankness and integrity. Any departure from the line of rectitude in such cases is not only bad in morals but involves a public wrong.”

Source: Driscoll v. Burlington-Bristol Bridge Co. 8 N.J. 433 (1952)