A day trip to Coney Island, once the largest amusement park in the United States, led me to the photograph. In the black-and-white image, a group of tribesmen, women, and children squats around a campfire. They’re barefoot and dressed in G-strings and tribal blankets. Several are looking at the camera and laughing. One man is pointing. Another is holding up a rock, as if he is about to throw it.

The photo could have been torn straight from the pages of …