What is the primary source of law in the United States?

The primary source of law in the United States is the Constitution. The Constitution serves as the foundational legal document for the entire country, establishing the framework of government, delineating the powers and responsibilities of different branches of government, and guaranteeing individual rights through the Bill of Rights and subsequent amendments. All laws made by Congress and state legislatures must align with the principles set forth in the Constitution.

While state laws, international treaties, and judicial rulings are important components of the legal system, they derive their authority from the Constitution. For instance, state laws can vary widely but must still conform to constitutional guidelines, and treaties must be ratified in accordance with constitutional processes. Judicial rulings interpret the law and can shape legal precedents, but they operate within the confines established by the Constitution. Thus, the Constitution is the supreme law of the land, making it the primary source of law in the United States.