The Constitution can only be changed through an ammendment. There have been only 27 amendments in the Constitution's history, the first ten being called "The Bill of Rights". To make an amendment to the Constitution, the change must be accepted first by a two-thirds majority in both houses of Congress, and then it must be ratified (accepted of approaved) by three quarters of all the states in the union. Of course such a large degree of agreement is rare, so amendments are rare.
Here is a constitution coloring sheet for your kids to enjoy coloring while learning about the United States.
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