Which document first outlined the rights of American citizens?

The Bill of Rights is the correct choice because it specifically enumerates the rights and freedoms guaranteed to American citizens. Ratified in 1791, this collection of the first ten amendments to the U.S. Constitution was designed to protect individual liberties against potential government overreach. These amendments address fundamental rights such as freedom of speech, the right to bear arms, and the right to due process, ensuring a clear articulation of the rights of individuals within the new republic.

The other documents listed do not serve the same primary purpose of explicitly outlining citizen rights. The U.S. Constitution, while foundational in establishing the framework of government, does not detail individual rights in the same manner until the addition of the Bill of Rights. The Articles of Confederation focused more on the structure of governance and lacked a comprehensive statement on individual rights. The Federalist Papers were a series of essays arguing for the ratification of the Constitution and discussing political theory, but they do not constitute a formal declaration of rights. Thus, it is the Bill of Rights that distinctly establishes and protects the rights of American citizens.