These were worn with no Highland regalia like sporans, dirks, and tartan kneesocks. They were also not worn with as part of the kilts sduits that were so popular with American boys in the late 19th century. Rather they are in essenmce simply tartan skirts. The Highland kilt is a basically a Tartan skirt covering the lower half of the body. Many of the kilts shown here worn by younger boys were bodice kilts.
Boys tend to be slender without pronounced hips.
This makes it difficult for these boys to wear kilts. The solution was to sew on a bodice to the kilt to hold it up. This is the same reason that younger boys wear suspender shorts to hold them up. Mothers Mothers of the era loved to dress their sons in kilts and fancy blouse . Many who hesitated to breech their sons still wearing dresses, saw the kiklt as a happy alternative to pants.