Which document outlines the structure of the U.S. government?

The U.S. Constitution is the foundational document that outlines the structure of the U.S. government. It establishes the framework for the federal government, detailing the separation of powers among the three branches: the legislative, executive, and judicial branches. Additionally, the Constitution enumerates the powers granted to each branch and stipulates the relationships between the states and the federal government. It serves as the supreme law of the land, providing the legal foundation for governance in the United States.

The other documents listed have significant historical importance but serve different purposes. The Declaration of Independence primarily expresses the colonies' intent to assert their independence from British rule and outlines the philosophical underpinnings of rights and government but does not establish a system of governance. The Articles of Confederation served as the first governing document for the U.S. after independence but were ultimately found inadequate due to the weak federal structure they created. The Bill of Rights consists of the first ten amendments to the Constitution, protecting individual liberties and rights, but it does not delineate the overall structure of government.