The United States Constitution is a founding document that sets out the government framework and powers of each branch of the government. This document essentially provided the United States with a structure for operating and for resolving issues that had not been addressed in previous documents. Perhaps the most recognized portion of the U.S. Constitution is its opening amendments known as the Bill of Rights.
Constitution Day is celebrated on September 17.
It is important to read The Constitution of the United States; it is even more important to understand what it means. These books and links will help you to better understand and interpret the United States Constitution.
A Companion to the United States Constitution and Its Amendments, 5th Edition by 
The Making of America by