After the leaders of the new United States wrote the Constitution, they had to get the thirteen states to agree to it. Some of the states didn’t want to agree unless they could add some specific rights for individual people. So in 1791 the United States added ten new rights to the Constitution. These are called the Bill of Rights. [Source]|
Without the Bill of Rights, there would be no US Constitution. Delegates, in 1787, were concerned that there were no safeguards against the Federal government at the expense of the state governments.
Thomas Jefferson agreed, writing, “A bill of rights is what the people are entitled to against every government on earth…and what no just government should refuse.” (December 1787 letter to James Madison)