I believe this tintype dates to the 1870s or so, based especially on the clothing of the adults--and, as far as I've been able to determine in researching, it is a fairly rare one; I've turned up a good number of school photos taken outside one room school houses produced as cabinet cards/paper printed photos, but tintype examples seem very few and far between. Quite a wonderful array of faces and postures and attitudes I think, with what seems to be a whole bunch of micro-dramas playing out within it, including one teacher tightly surrounded by children, clearly the favorite, and what I take for school administrators standing much more aloof in the doorway. With a tall, older looking boy standing in the back row, and a man in hat who I believe is Asian seated cross-legged in the foreground; so many stories.

3 1/2" x 2 7/16". Clipped corners, dark border and irregularities around the edges--making it feel all the more atmospheric to me.  Image clear and shows great detail. Lies flat, no notable dings or bends.