Mystery photo: man in top hat sitting on dead horse

The Sheboygan Press is asking its readers to help explain this unusual photograph taken in the 19th century.
In the photo, a dead horse lies in the street, roped off with string tied to stakes in the dirt road. A man in a top hat, bow tie and jacket sits on top of the horse, and people in the background are standing still, looking toward the camera.

"I always just assumed it was taken as a joke or something like that," said Bill Wangemann, Sheboygan city historian. "I was never able to find out anything about it. What the story behind that (picture) is, I don't have the foggiest notion."