Final answer:
Secede is the term that describes formally withdrawing membership from the union of states to form a new country with its own government.
Step-by-step explanation:
The term that describes formally withdrawing membership from the union of states that made up the United States of America in order to form a new country with its own government is secede. Secession is the act of a state or group of states breaking away from the existing political and legal framework.
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