Cox, Young, or Jenkins family ancestors (unidentified)

I've been cataloging some 50+ scanned images from a crumbling family album which belonged to my paternal grandmother, Amy Marguerite Cox* (nee Young). Its images date from the late 1800's to early 1900's. The latter were mostly taken in Ohio or Pennsylvania, U.S.A.; unless they had their names written on the backs, or at least the photographer's name and location, I have no way of dating or identifying most of them (especially those six or seven that are on metal plates).
In 1960, when I was finally deemed old enough to peruse the red velvet-covered album, I would ask grandma Cox just who were these people in these pictures? But she was mostly unable to identify them for me. (I now wonder if she just wouldn't say, or really didn't know, or couldn't remember, although she had to be put into a care home, in part due to senility, by the time she was in her 70's.)
*Amy's only child, John R. Cox, Jr., changed his name to John Howard when he was hired as an actor in Hollywood, California, in the early 1930's.
If you can identify any of these images, we sure would appreciate hearing from you. Thanks!