Civics: Our Common Law Justice System

Most people think of law as statutes — rules written down and passed by a legislature. But a large portion of American law is common law: judge-made law that develops through the accumulation of court decisions over time.

The common law tradition has its roots in medieval England, where royal courts began recording their decisions and, over centuries, developed a body of consistent legal principles. When the American colonies declared independence, they largely inherited this tradition. Today, common law governs vast areas including contracts, torts (civil wrongs like negligence), and property — at least in the absence of a statute that changes the rule.

How Common Law Develops

When a court decides a case, it doesn't just resolve the dispute between the parties — it also creates a record of how the law applies to that type of situation. Future courts facing similar facts look to those prior decisions for guidance. Over time, patterns emerge, and those patterns become the law.

This is why lawyers spend so much time studying old cases. A contract dispute filed today may be governed by principles traced to decisions made in 1889 or 1932. The past shapes the present.

A precedent is a prior court decision that provides a rule or principle applicable to a future case with similar facts. When courts apply precedent, they are not simply following orders — they are participating in an ongoing conversation about what the law means and how it applies.

The Role of Precedent

Precedent serves several important functions in the legal system:

• Consistency. Similar cases are treated similarly, which makes the law predictable.
• Fairness. It would be unjust for the law to be applied one way to one person and a different way to another simply because different judges had different opinions.
• Efficiency. Courts don't have to re-examine every legal question from scratch every time a case arises.
• Legitimacy. Law grounded in a long line of decisions carries more authority than law invented by a single judge on a single day.

Reading a Case as Precedent

Not every word a court writes becomes precedent. The holding — the court's actual decision on the legal question presented — is what binds future courts. Everything else a court says in passing is called dictum (or obiter dictum), meaning "something said in passing." Dictum can be persuasive but is not binding.

Stare decisis is the Latin phrase for the doctrine that courts should stand by prior decisions. Its full form is stare decisis et non quieta movere — "to stand by decisions and not disturb settled matters." It is the principle that makes precedent legally binding rather than merely informative.

Vertical and Horizontal Stare Decisis

Stare decisis operates in two directions:

• Vertical stare decisis means that lower courts must follow the decisions of higher courts within the same jurisdiction. A federal district court must follow a decision of its circuit's court of appeals; all federal courts must follow decisions of the United States Supreme Court.
• Horizontal stare decisis means that a court should generally follow its own prior decisions. It is not absolute — courts do sometimes overturn their own precedents — but departing from prior decisions requires strong justification.

Distinguishing Cases

A court that does not want to follow a precedent but cannot overrule it (because it's from a higher court) may "distinguish" the case — arguing that the facts of the current case are materially different from the prior case, so the prior rule does not apply. This is a legitimate legal technique that allows the law to develop without rigid uniformity.

Not all legal authority carries equal weight. When lawyers research the law, they evaluate sources along two dimensions: binding vs. persuasive and primary vs. secondary.

Binding vs. Persuasive Authority

Binding authority (also called mandatory authority) is legal authority that a court must follow when deciding a case. Persuasive authority is authority the court may follow but is not required to.

Whether authority is binding depends on two factors: (1) what kind of source it is, and (2) what jurisdiction it comes from.

Source	Type	Notes
U.S. Supreme Court case on a federal question	Binding	Binding on all federal and state courts nationwide
Your circuit's Court of Appeals decision	Binding	Binding on district courts in that circuit
Your state's Supreme Court on a state law issue	Binding	Binding on all lower courts in that state
A decision from a different circuit or state	Persuasive	Courts may look to it but need not follow
Law review articles, treatises, Restatements	Persuasive	Secondary sources; never binding, often influential
Concurring or dissenting opinions	Persuasive	Part of the case but not the holding

Primary vs. Secondary Sources

Primary sources are the law itself: constitutions, statutes, regulations, and court decisions. Secondary sources — treatises, law review articles, legal encyclopedias — explain, analyze, and synthesize primary sources. They can help you understand the law and find primary sources, but they are never binding on a court.

The United States has two distinct but parallel court systems: the federal courts and the state courts. They operate side by side, each with its own jurisdiction, its own judges, and its own hierarchy of appellate review.

Federal Courts

The federal court system is created by Article III of the Constitution. Federal courts have limited jurisdiction — they can only hear certain types of cases:

• Federal question jurisdiction: Cases arising under the U.S. Constitution, federal statutes, or treaties.
• Diversity jurisdiction: Cases between citizens of different states where the amount in controversy exceeds $75,000.
• Other constitutionally specified matters such as admiralty, bankruptcy, and patent cases.

State Courts

State courts are the workhorses of the American legal system, handling the vast majority of civil and criminal cases. They have general jurisdiction — meaning they can hear almost any case unless it must be in federal court. Divorce, most contract disputes, personal injury cases, and state criminal prosecutions all proceed in state court.

How the Systems Interact

The two systems are largely separate, but they intersect at key points:

• The U.S. Supreme Court sits atop both hierarchies for questions of federal law. It can review state court decisions — but only on the federal law issue, not on purely state law grounds.
• Federal courts applying state law must follow that state's highest court's interpretation of state law.
• Removal: A defendant in a state court case that qualifies for federal jurisdiction can sometimes "remove" the case to federal court.
• Certification: When a federal court faces an unresolved question of state law, it may certify the question to that state's supreme court for a definitive answer.

The Federal Circuits

The 94 federal district courts are grouped into 12 regional circuits, each served by a U.S. Court of Appeals. A thirteenth court — the U.S. Court of Appeals for the Federal Circuit — has nationwide jurisdiction over specialized subject matter like patents and international trade. Decisions from a circuit court bind all district courts within that circuit.

Circuit boundaries matter for citation: a decision from the Ninth Circuit is binding precedent in California, Oregon, Washington, and several other western states — but only persuasive authority in the Fifth Circuit. Knowing which circuit a court sits in tells you immediately which Court of Appeals governs it and which body of circuit precedent applies.

The National Reporter System

West Publishing's National Reporter System groups state appellate decisions into regional reporters. The reporter abbreviation in a citation — A.3d, S.W.3d, P.3d — tells you exactly which regional series contains the opinion and therefore which states' courts are covered by that volume.

Note that the reporter regions do not perfectly align with federal circuit boundaries — they reflect the geographic groupings West chose when it began publishing in the 1880s. Some states have their own separate state-specific reporters (Cal. Rptr., N.Y.S.) in addition to the regional series. When both exist, citations may include both — a state citation and a West reporter citation — known as a parallel citation.

A court decision only shapes the law if it can be found. The system by which opinions are published, organized, and cited is the infrastructure of the common law.

Published vs. Unpublished Opinions

Not every court decision is "published" in the formal legal sense. Courts designate some opinions for official publication in printed reporters — these are published opinions and are the primary form of precedent. Other decisions are designated unpublished, meaning the court did not intend them to be citable as precedent.

In federal courts, unpublished opinions were traditionally off-limits for citation, but Federal Rule of Appellate Procedure 32.1 (effective 2007) now permits citation to unpublished federal appellate opinions issued after January 1, 2007. State rules vary widely: some states still prohibit citing unpublished opinions, others allow it with restrictions, and some treat all opinions equally.

Reporters: The Traditional Publication System

Historically, court opinions were published in bound volumes called reporters. The citation system is built around reporters: a citation like Brown v. Board of Education, 347 U.S. 483 (1954) tells you the opinion is in volume 347 of the United States Reports beginning at page 483.

There are two kinds of reporters:

• Official reporters are published by or under the authority of the government. United States Reports (U.S.) is the official reporter for U.S. Supreme Court opinions. Many states have official reporters for their supreme courts and courts of appeals.
• Unofficial reporters are published by commercial legal publishers. West Publishing (now Thomson Reuters) built the most comprehensive system — the National Reporter System — which covers all U.S. jurisdictions with regional reporters (Pacific Reporter, Atlantic Reporter, etc.) and federal reporters (Federal Reporter, Federal Supplement).

Where to Find Court Opinions

The traditional research databases (Westlaw and Lexis) are comprehensive but expensive. A growing number of free and low-cost alternatives now cover federal and many state courts:

Finding Opinions for a Specific Jurisdiction

To find opinions from a specific court, the fastest path is usually:

1. Federal circuit opinions: Go to that circuit's court website (e.g., ca9.uscourts.gov for the Ninth Circuit) or search CourtListener with court:[circuit abbreviation].
2. U.S. District Court opinions: PACER for all filed documents; CourtListener indexes many district court opinions as well.
3. State supreme court opinions: Most state judicial websites post recent opinions. For historical opinions, CourtListener and the Caselaw Access Project have strong coverage.
4. State intermediate appellate courts: Coverage is spottier in free sources. Court websites, CourtListener, and Fastcase are your best bets without a commercial subscription.
5. Citator check: Before relying on any case, verify it hasn't been overruled. Free options are limited — Westlaw's KeyCite and Lexis's Shepard's are the gold standards. CourtListener's "Cited By" feature provides partial coverage.

Understanding common law, precedent, and the court hierarchy is not just an academic exercise. It changes how you read legal documents, how you evaluate legal arguments, and how you participate in civic life.

When you read a court opinion, you are watching law being made. The holding in that case will shape how courts decide similar disputes for years or decades to come. When you read a Supreme Court decision, you are reading a document with the force of law across the entire country.

Citation — the practice of precisely identifying legal sources — is the mechanism by which this system functions. Every legal citation is a pointer to a piece of the hierarchy: a case from a particular court in a particular jurisdiction at a particular moment in time. To understand a citation is to understand where that authority sits in the architecture of the law.