Common Law vs. Civil Law in America

Sep 6 / Dynamo Jakk


Welcome to this in-depth exploration of Common Law and Civil Law systems, especially as they pertain to the legal landscape of the United States. Given that the U.S. is a patchwork of federal, state, and even local laws, understanding the nuances between these two primary legal systems can provide a richer context for both ordinary citizens and legal professionals alike.

What Are Common Law and Civil Law?

In broad terms, Common Law, often referred to as "case law" or "judge-made law," is a legal system wherein court judgments establish legal precedents for future cases. Originating in medieval England, this system has been exported to many parts of the world, including the United States. On the other hand, Civil Law, rooted in Roman-Germanic tradition, is a legal system where comprehensive statutes and codes serve as the primary form of legal guidance. These statutes are typically created by legislative bodies and offer more specific sets of rules than Common Law.

Why Understanding These Systems is Crucial

The U.S. is unique in that it contains elements of both legal systems. Federal laws often work on principles of Common Law, while some states, like Louisiana, employ a Civil Law framework for their state laws. Understanding the distinctions between these systems is not just an academic exercise; it has practical implications for how laws are interpreted, how cases are adjudicated, and even how contracts are written and enforced. Whether you're an ordinary citizen navigating the complexities of everyday legal issues, or a practitioner looking to specialize, a working knowledge of both systems is invaluable.

Stay tuned as we delve deeper into each system, provide real-life precedents to elucidate key points, and explore the unique hybrid nature of American law.

Section 1: What is Common Law?

Definition and Origins

Common Law, often referred to as "judge-made law" or "case law," is a legal system in which the judicial decisions from individual cases establish legal precedents for future similar cases. This system originated in medieval England during the 12th and 13th centuries, under the reigns of Henry II and his successors. Judges began traveling around the country to resolve disputes, and their decisions were recorded and used as references for future cases, leading to the formation of a "common" system of laws. This legal tradition was exported to British colonies, including what would become the United States.

Characteristics of Common Law

Case Law as Precedent

In a Common Law system, judicial decisions serve as precedents that guide subsequent rulings. This means that judges often refer to past judgments to inform their decisions, creating a consistent body of law over time.

Adversarial System

Common Law also operates under an adversarial system where two sides present their arguments, and a neutral third party—a judge or jury—makes a determination based on the presented facts and applicable law. This differs from the inquisitorial system commonly found in Civil Law jurisdictions.

Role of Judges and Juries

While judges interpret the law, juries typically determine the facts of a case. Judges may also issue rulings when a jury is not present, but they often use precedents set by other judges in similar cases. In Common Law, judges play a critical role in shaping the law through their interpretations and judgments.

Example Precedents in Common Law

Brown v. Board of Education (1954)

One of the most groundbreaking precedents in American Common Law is the case of Brown v. Board of Education. In this case, the U.S. Supreme Court ruled that racial segregation in public schools was unconstitutional, effectively overturning the "separate but equal" doctrine established by Plessy v. Ferguson in 1896. This decision had a profound impact on civil rights and set the stage for future legislation and court rulings against racial discrimination.

Miranda v. Arizona (1966)

Another influential case is Miranda v. Arizona, which established the "Miranda Rights." These rights include the right to remain silent and the right to an attorney, and they must be read to a person upon arrest. This case has had a lasting impact on law enforcement procedures and the rights of the accused in the U.S.

In conclusion, Common Law is a dynamic and evolving system that relies heavily on judicial precedents. These precedents not only guide legal practitioners but also have a profound social and cultural impact, shaping our understanding of justice and fairness.

Section 2: What is Civil Law?

Having explored the complexities of Common Law, let's shift our focus to Civil Law—a system that contrasts sharply with Common Law in its origins, characteristics, and practices. This section will elucidate what Civil Law is, its historical roots, its defining features, and some influential precedents that have had a far-reaching impact.

Definition and Origins

Civil Law is a legal system that relies heavily on comprehensive, written laws and statutes to guide judges in adjudicating disputes. Its roots can be traced back to the Roman-Germanic tradition, particularly the Roman law as codified in the Corpus Juris Civilis during the reign of Emperor Justinian in the 6th century. This foundational text influenced many European legal systems and gave rise to the Civil Law tradition. The Napoleonic Code in France later provided a modern foundation for Civil Law, which has been adapted and implemented in many jurisdictions around the world.

Characteristics of Civil Law

Codified Statutes

Unlike Common Law, which relies on judicial precedents, Civil Law operates based on a comprehensive set of written codes and statutes that aim to cover all conceivable aspects of a particular legal area. These codes are often developed by legislative bodies and are regularly updated.

Inquisitorial System

Civil Law jurisdictions usually employ an inquisitorial system in which the judge plays a more active role in investigating the facts of a case. This stands in contrast to the adversarial system in Common Law, where the judge acts as a neutral referee between the prosecution and defense.

Role of Judges

In Civil Law, judges are typically career legal experts who have specialized training. They are not only tasked with applying the law but also with interpreting extensive codes and statutes. Judges in Civil Law systems often have more authority to shape the proceedings and outcomes, although they do so within the confines of written law rather than established precedent.

Example Precedents in Civil Law

Louisiana's Civil Code

Interestingly, within the United States, the state of Louisiana operates under a Civil Law system for its state laws, owing to its French and Spanish colonial history. The Louisiana Civil Code is a prime example of a codified system that stands in contrast to the Common Law tradition prevalent in the other 49 states.

Napoleonic Code

As one of the foundational documents for many Civil Law systems globally, the Napoleonic Code, established in the early 19th century in France, serves as a touchstone for how laws are structured and applied in Civil Law countries. It has influenced legal systems from Europe to Latin America and parts of Africa and Asia.

In summary, Civil Law offers a different perspective on legal adjudication, one that relies on comprehensive statutes and an inquisitorial system. It's a method that provides its own set of advantages and challenges, and understanding it is crucial for anyone engaged in international legal practice or residing in jurisdictions that employ this system.  

Section 3: Common Law vs. Civil Law in America

The American legal landscape is a fascinating blend of various traditions, primarily because it incorporates elements of both Common Law and Civil Law systems. In this section, we'll delve into how these two systems coexist in the U.S., serving different roles within the federal and state jurisdictions. We'll also look at the intriguing case of Louisiana, a state that has crafted a hybrid legal system.

Federal and State Laws

Common Law at the Federal Level

At the federal level, the United States largely operates under a Common Law system. Federal courts, including the Supreme Court, rely heavily on judicial precedents and the adversarial system to adjudicate disputes. Federal judges interpret the U.S. Constitution, federal statutes, and regulations, often referring to prior case law to make their rulings.

Civil Law in State Legislation

While most states also follow a Common Law tradition, elements of Civil Law can be found in the legislative process where comprehensive statutes are drafted to cover various legal matters. State legislatures frequently enact detailed codes dealing with issues such as family law, property law, and criminal law, resembling the codified nature of Civil Law systems.

Hybrid Systems

The Case of Louisiana

Louisiana presents a unique case within the United States, given its blend of Common Law and Civil Law traditions. Owing to its historical ties to France and Spain, Louisiana's state laws are primarily based on a Civil Law system, specifically the Louisiana Civil Code. However, the state is still part of the United States and, therefore, also incorporates Common Law principles, particularly in its procedural laws and federal matters. This creates a hybrid system that incorporates aspects of both traditions.

Why It Matters

The Louisiana example illustrates that the U.S. legal landscape isn't monolithic. Understanding the nuances of these mixed jurisdictions can be invaluable, especially for legal professionals involved in interstate legal matters or for businesses operating across state lines.

In conclusion, while Common Law remains the predominant legal system in the United States, influences of Civil Law are more prominent than one might initially think. From the legislative halls of state governments to the unique legal landscape of Louisiana, the interplay between these two systems enriches the American legal fabric, offering a multi-dimensional view of justice and governance.  

Section 4: Practical Implications

Understanding the theoretical aspects of Common Law and Civil Law is one thing, but how do these systems practically impact the lives of everyday citizens, legal professionals, and businesses? In this section, we'll explore the tangible implications of these differing systems, focusing on their effects on various aspects of American life.

For Ordinary Citizens

Everyday Life and Legal Issues

In Common Law jurisdictions, the focus on case law and precedents means that past judicial decisions can have a direct impact on a wide range of issues—from property rights to criminal justice. For example, your right to remain silent when arrested is a direct result of Miranda v. Arizona, a Common Law precedent. On the other hand, in Civil Law systems, citizens typically refer to codified statutes for legal guidance, which are often more detailed and specific.

Flexibility vs. Certainty

Common Law offers flexibility as judges have the latitude to interpret laws based on the unique circumstances of each case. In contrast, Civil Law provides more predictability as laws are clearly written out in comprehensive codes. Both have their pros and cons; flexibility can lead to more equitable outcomes, while predictability allows for better planning and understanding of one's legal obligations.

For Legal Practitioners


Legal professionals in Common Law systems often specialize in specific areas like constitutional law, criminal law, or contract law where judicial precedents play a significant role. Conversely, practitioners in Civil Law systems often specialize in understanding vast areas covered under codified statutes, such as civil codes or commercial codes.

Skill Sets

For Common Law attorneys, strong skills in legal research, case analysis, and oral argument are crucial, as they frequently have to refer to past judgments. In contrast, Civil Law lawyers need to excel at navigating and interpreting extensive written statutes, and their roles often involve more written advocacy.

For Businesses

Contracts and Dispute Resolution

In Common Law systems, contracts tend to be more exhaustive to cover various contingencies, given the lack of detailed statutes. This results in a greater reliance on case law to resolve disputes. In Civil Law systems, contracts are often shorter and less detailed, as many contingencies are already covered by the legal code. Thus, businesses operating in multiple states or internationally must be aware of these differences when drafting contracts.

Risk Assessment

Understanding the two systems also aids in business risk assessment. In a Common Law system, the flexibility and reliance on case law could lead to unpredictability in legal outcomes, whereas a Civil Law system offers more stability but less room for interpretation.

In summary, the distinctions between Common Law and Civil Law have wide-reaching implications that extend beyond the walls of courtrooms and legislative chambers. Whether you're an ordinary citizen curious about your legal rights, a budding legal practitioner deciding on a career path, or a business leader formulating contracts, having a nuanced understanding of these systems can offer both challenges and opportunities.

Section 5: Case Studies

To further illuminate the practical differences between Common Law and Civil Law, let's delve into some real-world scenarios. In this section, we'll examine how divorce proceedings and contract disputes would be handled under each system, including an examination of specific cases like Atlantic Marine Construction Co. v. U.S. District Court (2013).

Study 1: Divorce Proceedings

Common Law

In a Common Law system, divorce proceedings are largely influenced by judicial precedents. Courts rely on earlier decisions to resolve issues such as alimony, child custody, and division of property. For example, if a case involves a high-income spouse and a low-income spouse, the court may refer to similar cases to determine an equitable amount of alimony.

Civil Law

In contrast, Civil Law systems use comprehensive statutes to dictate divorce proceedings. The law often provides specific formulas or guidelines for alimony, child custody, and property division. In these jurisdictions, there's less room for judicial interpretation, leading to more predictable outcomes.

Key Takeaway

For ordinary citizens, understanding how divorce laws function in their jurisdiction can drastically impact the outcome of a divorce proceeding. The Common Law system allows for more judicial discretion but can be unpredictable, while Civil Law offers more clarity but less flexibility.

Study 2: Contract Disputes

Common Law

In the Common Law system, case law plays a significant role in the resolution of contract disputes. For instance, the U.S. Supreme Court case of Atlantic Marine Construction Co. v. U.S. District Court (2013) clarified that forum-selection clauses in contracts are generally enforceable. In this case, Atlantic Marine Construction had entered into a contract specifying that disputes would be settled in a Virginia court. However, when a dispute arose, the opposing party filed in Texas. The Supreme Court upheld the validity of the forum-selection clause, setting a precedent that influences similar contract disputes.

Civil Law

In Civil Law jurisdictions, contract disputes are generally resolved according to the explicit terms of the legal codes. There may be less focus on previous cases and more attention paid to what the written laws say about contract enforcement and dispute resolution. Any gaps in the contract are typically filled by the law rather than judicial interpretation.

Key Takeaway

For businesses, understanding how contract disputes are handled in their operating jurisdictions can help them draft more robust contracts and better manage legal risks. In Common Law systems, businesses may need to be aware of existing case law that could affect their contracts, while in Civil Law systems, a deep understanding of statutory laws is critical.

Through these case studies, we can see that Common Law and Civil Law systems offer different approaches to resolving legal issues. While Common Law provides flexibility and allows for a nuanced understanding of individual circumstances, Civil Law offers clarity and predictability through its comprehensive codes. Both have their merits and challenges, and the "best" system often depends on the specific needs and expectations of the parties involved.  


The legal landscape in America is a rich tapestry woven with threads of both Common Law and Civil Law traditions. As we have explored, Common Law, with its roots in medieval England, relies heavily on judicial precedents and an adversarial system. It offers flexibility and the ability for laws to adapt over time through judicial interpretation. Civil Law, tracing its origins to Roman-Germanic traditions, emphasizes comprehensive, written codes and statutes and employs an inquisitorial system that allows for predictability and clarity.

Understanding these two systems is not merely an academic exercise; it has practical implications for ordinary citizens, legal practitioners, and businesses alike. From divorce proceedings to contract disputes, the system under which you operate can have a significant impact on your legal journey. As illustrated by the unique hybrid system in Louisiana, even within a predominantly Common Law country like the United States, variations and nuances abound.

For anyone involved in legal matters, a grasp of these systems is invaluable. It informs how you approach legal issues, how you understand the potential outcomes, and ultimately, how you can navigate the complex yet fascinating world of American law.


  1. Friedman, Lawrence M. "A History of American Law," Third Edition. Oxford University Press, 2005.

  2. Merryman, John Henry, and Rogelio Pérez-Perdomo. "The Civil Law Tradition: An Introduction to the Legal Systems of Europe and Latin America," Fourth Edition. Stanford University Press, 2019.

  3. Posner, Richard A. "Economic Analysis of Law," Ninth Edition. Wolters Kluwer, 2014.

  4. "Atlantic Marine Construction Co. v. U.S. District Court for the Western District of Texas," 571 U.S. 49 (2013).

  5. Zimmerman, David, and Reinhard Zimmermann. "The Law of Obligations: Roman Foundations of the Civilian Tradition." Oxford University Press, 1996.


Further Reading

  • "Comparative Law" by Mathias Siems - A book that explores how different legal systems around the world operate, including Common Law and Civil Law.

  • "The Common Law" by Oliver Wendell Holmes, Jr. - A classic book that delves into the principles and philosophies underlying the Common Law system.

Glossary of Terms

  • Common Law: A legal system that relies on judicial precedents and an adversarial system for resolving disputes.

  • Civil Law: A legal system that uses comprehensive, written codes and statutes, generally with an inquisitorial system.

  • Adversarial System: A system of law where the role of the court is primarily that of an impartial referee between the prosecution and the defense.

  • Inquisitorial System: A system of law where the court is actively involved in investigating the facts of the case.

  • Case Law: Law established by judicial decisions in particular cases, as opposed to law created by legislative action.

  • Codified Statutes: Written laws that are enacted by a legislative body.

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