Which document serves as the foundation of U.S. law?

The U.S. Constitution serves as the foundation of U.S. law because it establishes the framework for the government and outlines the fundamental principles upon which the country operates. As the supreme law of the land, it provides the structure for federal government institutions, distributes powers among them, and delineates the rights of individuals. The Constitution not only establishes the legislative, executive, and judicial branches of government but also sets forth key amendments that protect civil liberties and individual rights. This foundational document has guided legal interpretations and the development of laws in the United States for over two centuries, making it central to the American legal system.

In contrast, the Declaration of Independence is a historical document asserting the colonies' freedom from British rule and outlining Enlightenment principles of governance but does not act as a legal framework. The Federalist Papers are a series of essays promoting the ratification of the Constitution and discussing its principles but are not legal documents themselves. The Emancipation Proclamation, while a significant executive order that aimed to abolish slavery, does not serve as the basis for laws governing the entire nation. Thus, the U.S. Constitution is rightly identified as the cornerstone of U.S. law.