What document outlines the foundational principles of the United States government?

The Constitution serves as the foundational document outlining the principles and framework of the United States government. It establishes the structure of government, delineates the powers and responsibilities of various branches, and sets forth the rights and liberties of citizens. Ratified in 1788, the Constitution not only created a system of checks and balances between the executive, legislative, and judicial branches but also introduced the concept of federalism, which balances power between national and state governments. Its preamble famously states the purpose of the government: to "form a more perfect union," among other goals.

On the other hand, while the Declaration of Independence articulates the philosophical and ideological justification for seeking independence from British rule and identifies inalienable rights, it does not establish a governmental framework. The Federalist Papers, a collection of essays written to advocate for the ratification of the Constitution, explain and defend the principles laid out in the Constitution but are not the document itself. The Bill of Rights comprises the first ten amendments to the Constitution, specifically addressing individual liberties and limiting governmental power but does not lay out the overall structure of government as the Constitution does.