Common law
The common lawso named because it was "common" to all the king's courts across Englandoriginated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. Prior to the Norman Conquest, much of England's legal business took place in the local folk courts of its various shires and hundreds. A variety of other individual courts also existed across the land: urban boroughs and merchant fairs held their own courts, as did the universities of Oxford and Cambridge, and large landholders also held their own manorial and seigniorial courts as needed. Additionally, the Catholic Church operated its own court system that adjudicated issues of canon law.
Seventh Amendment to the United States Constitution
Beyond all question, the common law here alluded to is not the common law of any individual state, (for it probably differs in all), but it is the common law of England, the grand reservoir of all our jurisprudence. It cannot be necessary for me to expound the grounds of this opinion, because they must be obvious to every person acquainted with the history of the law.