Section 3 - New States
New States may be admitted by the Congress into this Union; but no new States shall be formed or erected within the Jurisdiction of any other State; 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.
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; and nothing in this Constitution shall be so construed as to Prejudice any Claims of the United States, or of any particular State.
Editor's Note: You may wish to explore this further - here! As you read this think about why the federal government owns over 25% of the land mass of the United States - mostly in the west - and why they didn't turn that land over to the states as they did with the Eastern states, and what has been the consequence of that.