United States - This term has several meanings.

  1. It may be merely the name of a sovereign occupying the position analogous to that of other sovereigns in family of nations,
  2. it may designate territory over which sovereignty of United States extends,
  3. or it may be collective name of the states which are united by and under the Constitution.
Black's Law Dictionary, Sixth Edition
Hooven & Allison Co. v. Evatt, U.S. Ohio,
324 U.S. 652, 65 S.Ct. 870, 880, 89 L.Ed. 1252.

(i.e., defined by the Supreme Court in 1945)

United States -

  1. United States1 or U.S.1 (first meaning)

    The name of the sovereign nation, occupying the position of other sovereigns in the family of nations.

    In the first sense, the term "United States1" can refer to the nation, or the American empire, as Justice Marshall called it. The "United States1" is one member of the United Nations.

  2. United States2 or U.S.2 (second meaning)

    The federal government and the limited territory over which it exercises exclusive sovereign authority.

    Secondly, the term "United States2" can also refer to "the federal zone", which is a separate nation-state over which the Congress has exclusive legislative jurisdiction. In this sense, the term "United States2" is a singular phrase. It would be proper, for example, to say, "The United States2 is ..." or "Its jurisdiction is ..." and so on.

  3. United States3 or U.S.3 (third meaning)

    The collective name for the States united by and under the Constitution for the United States of America.

    Thirdly, the term "United States3" can refer to the 50 sovereign States which are united under the Constitution for the United States of America. In this third sense, the term "United States3" does not include the federal zone, because the Congress does not have exclusive legislative authority over any of the 50 sovereign States of the Union. In this sense, the term "United States3" is a plural, collective term. It would be proper therefore to say, "These United States3" or "The United States3 are ..." and so on.

The Federal Zone
by Mitch Modeleski