What are the most effective tools for establishing and preserving freedom?

I think it is the bill of right or the American Constitution

There are several documents to preserve freedom, but I think the most effective ones are the Bill of Rights, the Declaration of Independece, and the U.S. Constitution.

Explanation:

Now, how each document is used to estabilish and preserve freedom.

The Declaration of Independence is the theoretical part. It's just the attest that freedom is something important, and a right to be preserved. The Bill of Rights is where the idea of freedom is structured into 10 amendments. Here is where the State begins to operate, and laws can be created.And the U.S. Constitution is where all the laws, amends, political structures and the ways to preserve freedom attested previously by the Bill of Rights and the Declaration of Independence is formally developed. Then the Federal Government can operate.