Striking Early Segregated School Class Photograph

A second class photograph of students at all black school, found along with the class photo at the Bruce School in Houston l've also listed, that one dated 1919 and this one I presume from around the same time, perhaps just a bit earlier This is a real photo postcard, with the name William Henry Rivers (or similar; last name a bit hard to discern) written on reverse.  Another striking image, with several girls in sailor style dresses and the boys in jackets, making me think perhaps a Sunday school class, though I do not know for certain.   

5 1/2" x 3 3/8", with some light creases and stains but I think all the more beautiful for them.