Why and when did some American appellate courts add an 's' to the word 'Appeal' in their title?

Question

In England & Wales and most of the Commonwealth, the title of an appellate court is the Court of Appeal. The word 'appeal' is singular because it describes the purpose of the court in contrast to the Court of Justice (i.e. justice has been done by the court below, and the action now is that of appeal, similarly to the nomenclature of a Court of Cassation, a Court for the Correction of Errors, etc).

In the United States, some states follow the 'traditional' nomenclature—eg, the largest, California, has a Court of Appeal.

However, the federal courts, and many states, instead add an additional 's' to the title of appellate courts. Why is this, and where did it originate from?

Answer 1

On January 15, 1780, the Continental Congress resolved to establish "for the trial of all appeals from the courts of admiralty in these United States, in cases of capture", then a few lines later resolved "defraying the expence of said court of Appeals", and resolved actions "to carry into full and speedy execution the final decrees of the Court of Appeals", thus clearly establishing the acceptance of the first federal court of the US, the Court of Appeals in Cases of Capture. Some years earlier, Nov. 25 1775, the Continental Congress passed a number of resolutions pertaining to judiciously deal with seized goods in the course of the war (when there was no codified law or court system), where "prosecutions shall be commenced in the court of that colony in which the captures shall be made", but "cases an appeal shall be allowed to the Congress, or such person or persons as they shall appoint for the trial of appeals".

The Court of Appeal of England and Wales was created in 1875, which seems to be the first UK court specifically established for hearing appeals. There is no obvious linguistic reason for these different names assigned to the functionally same court in two countries, but once a name is officially given, it takes an act of Congress or Parliament to change the name.