Was there an Army OTC in the 1880s and would it have pertained to the Cavalry as well?

Answer 1

I do not believe there was any parallel to the current Reserve Officers Training Course (ROTC) that we have today -- professional officers in the 1880s were trained at the United States Military Academy (West Point) or the U.S. Naval Academy (Annapolis), or several other military schools (VMI, Citadel, and possibly others).