The Constitution of the United States prohibits both the United States and the separate states from granting titles of nobility. Moreover, certain U.S. citizens are prohibited from accepting foreign titles while holding office of profit or trust. The text follows:
Article I, Section 9, Clause 8. No title of nobility shall be granted by the United States: and no person holding any office of profit or trust under them, shall, without the consent of the Congress, accept of any present, emolument, office, or title, of any kind whatever, from any king, prince, or foreign state.
On this clause, the jurisprudence says (57 Am Jur 2d Name, sect. 37) that "the possibility that a judicial change of name would imply a conferring of a title of nobility, royalty or superior rank has been successfully raised in objection to petitions for change of name" (the example cited was a change from Jama to von Jama).
Note that Congress's power to consent to the acceptance of gifts and decorations has been delegated to the various agencies by the Foreign Gifts and Decorations Act of 1966 (5 USC 7342) (the concurring approval of the Secretary of State ceased to be required in 1977, PL 95-105). Various decorations had been authorized for wearing by an act of 1956, and service medals and ribbons from multilateral organizations other than the UN are governed by regulations of the Secretary of Defense, under an executive order of 1969 (strictly speaking, such organizations are not "foreign states").
Article I, Section 10. No state shall enter into any treaty, alliance, or confederation; grant letters of marque and reprisal; coin money; emit bills of credit; make anything but gold and silver coin a tender in payment of debts; pass any bill of attainder, ex post facto law, or law impairing the obligation of contracts, or grant any title of nobility.
Concerning this last clause, it is said (16 Am Jur 2d sect. 283, footnote 25) that "this prohibition has not controlled the outcome of any significant legislation." But, as Alan Terlep (ximenez@stimpy.us.itd.umich.edu) notes, it did not prevent the legislature of the state of Michigan from passing a resolution naming Aretha Franklin "Queen of Soul."
Furthermore, there is a law which requires aliens petitioning for citizenship to renounce all titles of nobility. The text follows, from 8 USC section 1448, subsection (b):
"In case the person petitioning for naturalization has borne any hereditary title, or has been of any of the orders of nobility in any foreign state, the petitioner shall in addition to complying with the requirements of subsection (a) [omitted] of this section, make under oath in open court in the court in which the petition for naturalization is made, an express renunciation of such title or order of nobility, and such renunication shall be recorded in the court as part of the proceedings."
The Code of Federal Regulations (8 CFR 337.1) accordingly provides the following:
A petitioner or applicant for naturalization who has borne any hereditary
title or has been of any of the orders of nobility in any foreign state shall,
in addition to taking the oath of allegiance prescribed in paragraph (a) of
this section, make under oath or affirmation in public an express renunciation
of such title or order of nobility, in the following form:
(1) I further renounce the title of (give title or titles) which I have
heretofore held; or
(2) I further renounce the order of nobility (give the order of nobility)
to which I have heretofore belonged.
A 1944 case decided that, since the Weimar constitution of Germany abolished marks of nobility so that they were considered only to be part of the name, a German national had no title or order of nobility to renlunce, and he was free to keep as part of his name the portion wich formerly indicated a mark of nobility.
The U.S. cannot grant titles of nobility, and foreigners who are naturalized must renounce all titles, but there is nothing that prevents a U.S. citizen from inheriting a title from abroad and using it as he pleases, unless it leads him or her to pledge alliegance to a foreign power, a case which could be grounds for loss of citizenship. Examples of US citizens holding British titles include the 5th Earl of Wharcliffe (Richard Alan Montagu Stuart Wortley, of Cumberland ME; his eldest son is viscount Carlton), and Sir John Dunbar, Bt, who was succeeded in August 1993 by his son Sir Michael Dunbar, 14th Bt, a colonel in the US Air Force.
In the 11th Congress (1809-11), an amendment to the Constitution was proposed but never ratified by the required 3/4 of the States. here is the amendment:
If any citizen of the United States shall accept, claim, receive or retain any title of nobility or honour, or shall, without the consent of Congress, accept and retain any present, pension, office or emolument of any kind whatever, from any emperor, king, prince or foreign power, such person shall cease to be a citizen of the United States, and shall be incapable of holding any office of trust or profit under them, or either of them.
In any case, there were eight Lords Proprietors, the eldest of whom
was the "palatine" and head of the province...there's a clear
interpretive problem in the case of the first article:
The eldest of the lord proprietors shall be palatine;and, upon the decease
of the palatine, the eldest of the seven surviving proprietors shall always
succeed him.
So what happens when either the dying palatine or one of the other
proprietors would be succeeded by a relative who was older than the palatine??
The other seven proprietors had their choice, in order of age, of the offices of admiral, chamberlain, chancellor, constable, chief justice, high steward, or treasurer...musical chairs being facilitated when any of the offices opened up, the successor to the decedent taking the office opened after the musical chairs. Each proprietor headed a "court" attached to his office, the palatine empowered to pull rank on any of them(and his own court consisting of the proprietors themselves).
The province was divided into counties. Each county consisted of eight signories, one for each proprietor, eight baronies, four given to the county landgrave and two to each of its two cassiques, and four precincts of six colonies each for the others. Every county had a sheriff, every precinct a justice of the peace, appointed from among its freeholders by the palatine's court. Every colony had an elected constable.
It was illegal under the Fundamental Constitutions to take money for representing someone in court, or to write books of commentary on laws.
Landgraves and cassiques could both sit in the colonial parliament, which also included the proprietors and one freeholder elected from every precinct. They met as one chamber and each had one vote. The four estates could vote separately on constitutionality of legislation. No one could hold more than one dignity. Titles could be inherited by all descendants, not just heirs male, but an heir general succeeding had to take the name and arms of the original grantee.
Manors with certain local government powers could be created by the palatine's court for those who owned 3,000-12,000 acres but were not landgraves or cassiques.(XXI "Every lord od a manor, within his manor, shall have all the powers, jurisdictions, and privileges, which a landgrave or cassique hath in his baronies.").
The Oxford Guide to Heraldry (pp. 159-61) mentions two titles created, in 1709 and in 1715. The Carolina herald died insolvent in 1715 and no successor was appointed; but the herald's business was to grant arms to the landgraves and cassiques, not create them, so in principle more titles could have been created. There is a color plate showing what the robes and insignia would have looked like.
See also the Heirs of Heritary Landgraves & Cassiques, Society of South Carolina.