The only way you can do that is if Congress signs off on it.
Every other state has an incentive not to permit that, because then that state gets two senators of its own.
Congress has only ever permitted a state to split a single time – West Virginia from Virginia, during the American Civil War, where West Virginia was willing to side with the Union, and contained some militarily-important rail and water infrastructure.
Texas also negotiated the right to have the ability to split into five states if it wanted down the line at the time it joined, but I recall reading that it was considered to no longer be an exerciseable option after the American Civil War.
New States may be admitted by the Congress into this Union; but no new State 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.[4]
EDIT2: Correction; Kentucky was also split from Virginia and Maine from Massachusetts. The Kentucky split happened before the US Constitution was ratified. Maine was part of the Missouri Compromise, to keep slave and free states in balance when Missouri joined as a slave state.
The only way you can do that is if Congress signs off on it.
Every other state has an incentive not to permit that, because then that state gets two senators of its own.
Congress has only ever permitted a state to split a single time – West Virginia from Virginia, during the American Civil War, where West Virginia was willing to side with the Union, and contained some militarily-important rail and water infrastructure.
Texas also negotiated the right to have the ability to split into five states if it wanted down the line at the time it joined, but I recall reading that it was considered to no longer be an exerciseable option after the American Civil War.
EDIT:
https://en.wikipedia.org/wiki/Admission_to_the_Union
EDIT2: Correction; Kentucky was also split from Virginia and Maine from Massachusetts. The Kentucky split happened before the US Constitution was ratified. Maine was part of the Missouri Compromise, to keep slave and free states in balance when Missouri joined as a slave state.