The act of Congress of January 11, 1805, which created Michigan Territory out of Indiana Territory, provided that the new territory should have a government "in all respects similar" to that provided for the Northwest Territory by the Ordinance of 1787. The Ordinance had provided for the appointment of a court to consist of three judges who should have "a common law jurisdiction. "
William W. Blume,
Chancery Practice on the American Frontier: A Study of the Records of the Supreme Court of Michigan Territory, 1805-1836,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol59/iss1/3