When the Constitution was written, there was no Bill of Rights in it. This was a concern for those who didn’t support the Constitution. These people were called the Anti-Federalists. The Anti-Federalists believed that without a Bill of Rights, people would lose their freedoms. They were concerned the federal government would have too much power, which could possibly include taking away the freedoms of the people. They were very concerned we would go back to the days when we were colonies of Great Britain. They remembered how the King removed some basic rights, such as trial by jury, which the colonists had as British citizens. They didn’t want to go back to a situation like that again.
The Federalists were hesitant to add a Bill of Rights to the Constitution. They believed the Constitution guaranteed the people that their rights would be protected. They believed adding the Bill of Rights was redundant and unnecessary. The Federalists did agree to add the Bill of Rights when they realized that some states wouldn't ratify the Constitution until there was an agreement to add the Bill of Rights to the Constitution.