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Legal Research Starting Points: Primary Sources

Primary Sources of Law

What are Primary Sources of Law?

They are the official pronouncements of governmental lawmakers (agencies, courts, legislatures).  They include court decisions, legislation, and regulations that form the basis of the legal doctrine.

Remember that not all primary sources have the same force for all purposes.  Decisions of the state supreme court are mandatory authority in its jurisdiction (the state) and must be followed by lower state courts. A state statute is also mandatory authority. However, other primary sources are only persuasive authority.  For example, a court in one state may be influenced by decisions in other states but need not follow them.

The Constitution is the foundation of our legal system. Other sources of law come from each of the three branches of government.


The framers of the Constitution of the United States created a government with three separate branches, each with its own distinct powers. Governmental power and functions in the United States rest in three branches of government: the legislative, judicial, and executive. Article I of the Constitution defines the legislative branch and vests power to legislate in the Congress of the United States. The executive powers of the President are defined in Article 2. Article 3 places judicial power in the hands of one Supreme Court and inferior courts as Congress sees necessary to establish. State governments generally follow the same structure as the federal system.