Agassiz School circa 1901-07
This picture is very similar to one that can be found online, but these is a subtle difference in the location of the camera. In the lower left, it says "No. 3 Pub. by the E.W. Clark Co." A Web search gives up no reference to a Clark post card company, but there may be another explanation. There was an E.W. Clark dry goods store in the White Block on Centre street, just around the corner from the school. I suspect that Mr Clark may have had a series of post cards featuring local scenes printed up to sell at his store. The Library of Congress web site tells us that a post card of this design would have been produced during the years 1901-1907. The school was built in 1902, so that cuts one year off the range.
correction: the school was built in 1892, not 1902.