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Circuit Riders: Legal Research Training for Non-Lawyers

Sources of Law

To understand the legal research process, one must first understand how the 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 constitutions, statutes and ordinances, rules and regulations, and 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.

Three Branches of Government
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.



Legislative Branch

Federal, state, and local legislative branches are each responsible for enacting their own laws.

The United States Congress enacts federal laws called statutes that are compiled by subject in the United States Code. For example, in 1993, Congress enacted a statute called the Family and Medical Leave Act, which entitles an employee to twelve weeks of unpaid leave if she has a serious health condition.

The South Carolina General Assembly enacts state statutes that are arranged by subject in the South Carolina Code Annotated. For example, as part of the South Carolina's Children's Code, the South Carolina General Assembly passed a law giving family courts the authority to order absent parents to pay child support.

Cities and counties enact laws called ordinances that are organized by subject in municipal codes. For example, in recent years, many cities and counties in South Carolina have enacted smoking ordinances banning smoking in both public places and places of employment.

Executive Branch

Federal and state executive branches are responsible for enforcing and implementing federal and state laws.

This is accomplished when Congress and state legislative bodies give federal and state administrative agencies the power to write rules and regulations to implement and enforce the laws they pass.

For example, when the U.S. Congress passed the Family and Medical Leave Act, it gave the U.S. Department of Labor the responsibility and power to write regulations to enforce its provisions.

And, when the South Carolina Assembly passed the South Carolina Children's Code, it gave the South Carolina Department of Social Services the task of writing regulations to serve as guidelines for family courts to use in calculating the amount of child support an absent parent is required to pay.

Judicial Branch

Federal and state court systems interpret federal and state statutes and regulations and determine their constitutionality.

For example, the federal court in Miller v. AT&T Corporation, 250 F.3d 820 (4th Cir. 2001), interpreted the Family and Medical Leave Act passed by Congress and the regulations created by the Department of Labor to entitle Ms. Miller to medical leave because her employer should have treated her flu as a serious health condition.

The South Carolina Supreme Court in Arnal v. Arnal, 371 S.C. 10, 636 S.E.2d 864 (2006), interpreted the South Carolina Children's Code enacted by the South Carolina General Assembly and the regulations issued by the South Carolina Department of Social Services to allow family courts to assign income to parents found to be voluntarily underemployed for purposes of calculating their ability to pay child support.

Case Law
Federal and state courts create case law in their respective jurisdictions by resolving ambiguous language in statutes and regulations.

Courts also resolve disputes where no statute or regulation applies, resulting in a body of judge-made law called common law. For example, the elements required to recover for claims such as negligence or fraud in South Carolina are determined by case law, not statutes. As individual disputes arise, South Carolina courts decide if those elements are present and if common law defenses apply to reduce or prevent recovery. The courts’ decisions are guided by precedent.

Judges apply rules from prior court decisions to cases that come before them with similar issues. This process is called stare decisis, which is Latin for “let the decision stand.” The rules applied from prior cases are known as precedent.
The doctrine of precedent allows lawyers to advise their clients by predicting the likely outcome of an existing legal dispute or a proposed action.