My assumption is this picture was taken in 1897 when he was 19 years old and in college either in Rockford, IL or Madison, WI. There is no writing on the back of the picture to provide any clarity. I like this picture because of my own children’s involvement in band. For instance, my son Brandon also plays the euphonium and has also played tuba and sousaphone (although his primary instrument is trombone). I’ve been a trombone player in the past and know my cousins have played instruments as well.
The 2nd picture attached includes two of Dwight Sr’s. grandchildren, Joann and Dwight in their Jr. High School Band.