The historical document that established the framework for the U.S. government is the Constitution of the United States, ratified in 1788. This foundational document outlines the structure, powers, and limitations of the federal government and incorporates the principles of democracy, federalism, and separation of powers among the legislative, executive, and judicial branches. It was crafted to create a stronger national government capable of uniting the diverse states while protecting individual rights and liberties. The Constitution has been amended many times, with the Bill of Rights being a crucial addition, safeguarding essential freedoms for American citizens.