What two companies built forts for the fur trade in oregon country?

The Pacific Fur Company and the Hudson's Bay Company, both made forts for fur trading

answer: the apache, comanche, kiowa, crow, and osage tribes are plains indians.  

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".