• The acquisition of Louisiana set the stage for the first real clash between common law and civil law in America.   Territorial governor William C.C. Claiborne had to steer a careful course between old settlers and merchants, who were used to the established civil law system and opposed change, and the influx of new American settlers who believed the common law should come with them. 

• Claiborne gradually introduced trial by jury and other procedural features of the common law to Louisiana.  He was aided by Edward Livingston, a prominent New York jurist who had recently moved to the new territory.  Livingston prepared a code of court procedures that mixed common and civil law features (1805), and he later helped revise Louisiana’s French-based Civil Code to incorporate some common-law elements (1808). 

• The Code was revised in 1825 to incorporate still more common-law features.  But the legislature carefully preserved the French and Spanish core of Louisiana law, and even arranged for an English translation of the Partidas to aid in the cause.  Louisiana’s supreme court also continued to look to civil law for guidance in its decisions.  Gradually, the supreme court built up a body of case law that reinforced the state’s unique mix of common and civil law – a mix that remains distinctive to this day.     

Florida

• Common law met less resistance in Florida than in Louisiana because there were fewer old settlers to oppose it.  Andrew Jackson, the first territorial governor [ck], followed Claiborne’s lead:  he quickly introduced a court system, court procedures and a criminal code based on American common-law practices but he encouraged continued use of Spanish civil law in other fields.  As more Americans poured into the territory, common law rules replaced civil law rules in those fields as well, and by the 1840s Florida was a common-law state.