OK one of the button in the back shirts. Omer Madison Kem sod house Broken Bow, Nebraska 1886, (note how nice it is we have location, time and even a name).
No buttons in front, this style seemed to have some popularity in the later 1880's and into the 90's.
Yes, I'm guessing the watermelon is bitter, the reason the kids are making faces, often happens in hot dry weather and Omar must sharpen his knife on his foot cranked grindstone.
I'll find some more, had some nice photobucket files but they are holding them hostage, can't hardly even open the pictures let alone link them.