I have done a series of articles on Military Justice in the American Revolution for the Brigade Dispatch, journal of the Brigade of the American Revolution. One of the best overviews of military justice I came across was by
Winthrop, William. Military Law and Precedents. 2d edition. Washington, DC: Govt. Printing Office, 1920.
It will point you toward further sources.
In the American Revolution, the Continental Army used Courts of Inquiry for among other things, officer cases. The use was similar to a civilian grand jury or today's military's Article 32 investigation. Basically it saved the commander from putting 13 officers on a court martial until the court of inquiry (usually 3-5 officers) found that a trial was warranted. The interesting thing was that the Rules and Articles of War which set out the military justice system back then had no mention of courts of inquiry. Best I can figure, the Continental Army emulated the British Army in holding courts of inquiry. Our courts martial system mimiced them, and our Rules and Articles of War were almost word for word the same as theirs.
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