Mystery photos

When I was going through a box of photos, slides, and negatives that we found stashed amongst my father's things, we found some mystery photos. We have no idea who any of these people are. Nor where the photos were taken. But, based upon the time frame of many of the photos in the box, I would assume that they were taken in the late 1940s or early 1950s. They may be related on the Kline side of the family. Any suggestions?