The historical document that established the system of government in the United States is the Constitution, ratified in 1788. This foundational document outlines the framework of the U.S. government and is comprised of a preamble and seven articles, detailing the roles and powers of the legislative, executive, and judicial branches. It also includes the Bill of Rights, which encompasses the first ten amendments, guaranteeing individual liberties and protections. The Constitution has been a dynamic document, allowing for amendments and interpretations to adapt to changing societal needs. It remains a cornerstone of American democracy and law.