Constitution of the United States of America
Article IV: Interstate Relations
Article 4, Section 3:  New States, Territories

 New States may be admitted by the Congress into this

4.3.2  but no new State shall be formed or erected within the
Jurisdiction of any other State;

4.3.3  nor any State be formed by the Junction of two or more
States, or Parts of States, without the Consent of the Legislatures
of the States concerned as well as of the Congress.

4.3.4  The Congress shall have Power to dispose of and make all
needful Rules and Regulations respecting the Territory or other
Property belonging to the United States;

4.3.5  and nothing in this Constitution shall be so construed as to
Prejudice any Claims of the United States, or of any particular