Answer:
27 times.
Step-by-step explanation:
The highest law of the U.S. is the Constitution of the United States. It was approved on 17th September 1787 by the Constitutional Convention in Philadelphia. However, during the course of time, the Thirteen States of the United States put it into effect. Since then the Constitution of the United States has been changed or modified 27 times. Among these changes, those primary ten changes are together known as the Bill of Rights.