When the Territory of Michigan came into existence July i, 1805, it found a system of jurisprudence in operation which had been adopted by the Governor and Judges of the Northwest Territory from the laws of Pennsylvania, due no doubt, to the fact that Gov. Arthur St. Clair had lived some years in that State, had been a member of its Board of Censors, a magistrate, and was familiar with its judicial system which provided a-Court of General Quarter Sessions of the Peace in each county composed of Justices of the Peace, a Court of Common Pleas in each County, a Circuit Court composed of one or more of the judges of the Supreme Court for the trial of issues joined in that Court, and finally the Supreme or General Court, having both original and appellate jurisdiction. One of the officials provided in this system was the Chief Clerk of the Court of Common Pleas or the Prothonotary; in that part of the Territory, which later became Michigan, there never was but one Prothonotary, Peter Audrain of Detroit.
W L. Jenks,
Judicial System of Michigan under Governor and Judges,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol18/iss1/3