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Circuit Riders: Sources of Law

Basic Legal Research Guide

Sources of Law

To understand the legal research process, begin with how our legal system works. The United States legal system has two major systems of government, federal and state, each of which has its own set of laws.

The four sources of federal and state law are:

  1. constitutions;
  2. statutes and ordinances;
  3. rules and regulations; and
  4. case law.

Constitutions are the foundation of our legal system. All governmental authority flows from the United States Constitution and the state constitutions.
The United States Constitution is the "supreme law of the land" and no laws, state or federal, may violate it. Each state has its own constitution. The laws of a particular state may not conflict with the constitution of that state or the U.S. Constitution.

Federal and State Laws

The Separation of Powers doctrine divides governmental authority among three branches: Legislative, Executive, and Judicial. These three branches of federal and state government are responsible for creating the remaining sources of law

  • Legislative branches enact laws called statutes and ordinances.
  • Executive branches enforce and implement these laws through rules and regulations.
  • Judicial branches interpret these laws by deciding cases and issuing written opinions.

Flowcharts of the federal and state legal systems as described above.

This guide will cover how to research the laws created by all three branches of the government.