At least two ghostly mysteries gained national attention in the early 1870s, when the U.S. was still feeling the trauma of the Civil War. One concerns a phantom that roamed Memphis’s Brinkley Female College in 1871. You can read about that here.
The other ghost was also drawn to a school, but this time, an elementary school in Newburyport, Massachusetts. The earliest report I’ve found so far was printed in late November, 1872. The writer of this article, which appeared in The New Orleans Republican, opens by listing the alleged manifestations: first rappings, then latches lifted, and finally a pale boy who appeared at a window and glided inside — but who vanished into nothingness when the teacher attempted to grab him. The writer ends by expressing not just skepticism but outrage at the seriousness given to the allegations, especially the investigation promised by a school committee. “Of course there is no ghost,” the reporter insists, “and no face of a deceased boy had been seen looking through the window, and no ghost has been grasped at by the teacher.”