C---“United States” is a Constitutional term of art referring to federal actors, elevated by the Supremacy Clause.
Paul Mitchell 15, Mitchell is the Founder of the Supreme Law Firm, previous Vice President for Legal Affairs and Counsel to an Arizona Trust, Private Attorney General, Criminal Investigator, 2015, Letter to colleagues, http://www.supremelaw.org/letters/us-v-usa.htm.
Note also that those Articles clearly distinguished "United States of America" from "United States" in Congress assembled. The States formally delegated certain powers to the federal government, which is clearly identified in those Articles as the "United States". Therefore, the "United States of America" now refer to the 50 States of the Union, and the term "United States" refers to the federal government. The term "United States" is the term that is used consistently now throughout Title 28 to refer to the federal government domiciled in D.C. There is only ONE PLACE in all of Title 28 where the term "United States of America" is used, and there it is used in correct contradistinction to "United States": Because Title 28 contains statutes which govern all federal courts, the consistent use of "United States" to refer to the federal government carries enormous weight. Title 28 is the latest word on this subject, as revised, codified and enacted into positive law on June 25, 1948. Moreover, the elevates Title 28 to the status of supreme Law of the Land.