Figure 1.--This unidentified portrait was taken by W.H. Grover in Springfield, Missouri. It is undated but would have been taken in the late 1890s or early 1900s. All three brothers wear blouses, floppy bows, and blouses with kneepants. Note the two types of front opening. The boy on the left has a front flap wityh side buttons. The bpy on the right has a center fly.

We have only limited information here, but as far as we cam tell there appears to have been two basic types of front openings for boys trousers in the 1900s. We beliece that bloomer knickers commonly had front flaps with buttons at the sides. I'm not sure how this worked when the bloomer knickers had bodices. Kneepants were also done with a front flap. This appears to have been more common for older than younger boys. I am not sure why. The other approach was the modern fly. The vertical opening here would have buttoned in the 1900s. Zippers of course were not yet used on pants.