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LRAW Research Fall 2024

Sources of Law


To understand the legal research process, one must first understand how the legal system works. The United States has three systems of government, federal, state, and tribal, each of which has its own set of laws. Elizabeth Reese. The Other American Law. 73 Stan.L.Rev. 555 (2021). The four sources of federal and state law are (1) constitutions, (2) statutes and ordinances, (3) rules and regulations, and (4) case law. Though we will not be discussing or studying any tribal law this year, know that tribal laws come from these same four (4) sources, and also from a fifth (5) source - customs and traditions.


Constitutions are foundational to our legal systems. Federal and state governmental authority flows from the United States Constitution and the state constitutions. Tribal powers are inherent rather than derived from the federal government and Tribal nations possess all powers of a sovereign government except as limited by lawful federal authority. See, Worcester v Georgia, 31 U.S. (6 Pet.) 515, 559 (1832) The federal government has limited inherent tribal authority by treaty, by statute, and in some instances, by judge-made federal common law. Cohen's Handbook of Federal Indian Law. § 4.02. (Neil Jessup, ed, 2019).

The United States Constitution is the supreme law of the land, and no laws, state, federal, or tribal, 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 with the U.S. Constitution. This same limitation has been placed on Tribal nations via treaty, statute, and by judge-made federal common law (case law).

Three Branches of Government

The Separation of Powers doctrine divides governmental authority among three branches: Legislative, Executive, and Judicial. Some tribes have adopted this three-branches of government system, but not all.


Legislative branch creates statutes and Ordinances. Executive branch creates Rules and Regulations. Judicial branch creates Case Law.

These three branches in federal and state governments 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, rules, and regulations by deciding cases and issuing written opinions.


Federal System: US Constitution, then Federal Government which is divided into 3 Branches, Legislative Enacts Laws, Executive Enforces Laws, Judicial Interprets Laws. State System: US Constitution, then State Constitutions, State Government is divided into 3 Branches, Legislative Enacts Laws, Executive Enforces Laws, Judicial Interprets Laws.

Legislative Branch


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

The United States Congress enacts federal laws—also called federal 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 of Laws. For example, the South Carolina General Assembly passed a law giving family courts the authority to order absent parents to pay child support. That statute is part of the South Carolina's Children's Code.

Executive Branch

White House

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

This is accomplished when Congress or state legislative bodies give federal or 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 General 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

Supreme CourtFederal and state court systems interpret federal and state statutes and regulations and determine their constitutionality and the applicability of the law to the facts.

For example, the federal court in Miller v. AT&T Corporation, 250 F.3d 820 (4th Cir. 2001), interpreted (1) a federal statute enacted by Congress, known as the Family and Medical Leave Act, and (2) related federal regulations created by the Department of Labor.

The South Carolina Supreme Court in Arnal v. Arnal, 371 S.C. 10, 636 S.E.2d 864 (2006), interpreted (1) a collection of state statutes known as the South Carolina Children's Code, and (2) related state regulations issued by the South Carolina Department of Social Services.

Case Law

Federal and state courts create case law in their respective jurisdictions in three ways. First, court decisions can create law by interpreting ambiguous language in constitutions, statutes, and regulations.

Second, court decisions can announce new principles of law where no statute or regulation applies, creating a body of judge-made law called common law, a subset of case 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. This means negligence and fraud are common-law claims.

Third, court decisions create case law by applying the law (whether common law, constitutional law, statutory law, or regulatory law) to new situations. Even when a court is not clarifying legal language or adding a new principle of common law, each new judicial opinion adds to the body of case law by providing an example of how the law applies to an individual case.


The principle of stare decisis, which is Latin for “let the decision stand,” means that judges follow prior court decisions when deciding cases that come before them with the same legal issue, meaning (1) governed by the same law and (2) having similar facts. A binding prior court decision is known as precedent.

Stare decisis allows lawyers to advise their clients by predicting the likely outcome of a legal dispute or a proposed action. If the lawyer has researched prior court decisions on the same legal issue, meaning (1) governed by the same law and (2) having similar facts, the lawyer can predict that the outcome may be the same if a court addresses the client's legal dispute or proposed action.