What Is the American Legal System Influenced By?

The law of the United States is based on a number of factors, including English common law and Roman civil law. It has been influenced by foreign laws such as French civil law and Germanic tribal customary laws. At both the federal and state levels, it derives from judicial decisions made in courts that resolve disputes brought before them.

In general, U.S. courts follow precedents set forth in appellate court rulings that become accepted as case law over time; however, there are many exceptions to this rule which have resulted in some significant departures from precedent at various points throughout our history. The primary sources of American Law are constitutional law, statutory law, treaties, administrative regulations, and common law.


American Common Law


The United States and most Commonwealth countries are heirs to the common law legal tradition of England. The practices allowed under English Common Law were specifically outlawed by our Constitution, such as bills of attainder and general search warrants. However, those prohibitions do not apply within this country’s borders.

So U.S. courts still rely heavily on stare decisis (the Latin phrase meaning “to stand before.”). American judges will often take an existing precedent from one case if applicable in another or closely related situation. They also follow this procedure for a new circumstance with little precedent because they know how important consistency can be when applying precedents across various cases.


State Law


The passage of time has led to state courts and legislatures expanding, overruling, or modifying the common law. As a result, we observe that laws in any given State invariably differ from sister states due to their variations within each area, such as tort law. This makes up 50 separate systems across America that come into conflict with other jurisdictions over certain matters.

All states have a legislative, executive, and judicial branch. In some instances, codification is treated as merely restating common law regarding subjects covered by previous judges’ decisions. However, in other cases, the codes get a liberal interpretation from all three branches of government, emphasizing how they apply within current legal frameworks established through court hearings or legislation passed over time.

All such laws have their roots in the old English laws as the US was a former British colony, overtime the laws have been changed and modified, but we can still find British traces in our laws.

To learn more about what influences U.S. laws, visit our blog section.