All of the following became u. s. possession as a result of the spanish-american war except a. mexico b. puerto rico c. guam d. the philippines

The answer is Mexico.

c

explanation:

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".