Isaac W. Sprague was an entertainer and sideshow performer, billed as the living human skeleton.
Sprague in 1867, age 26
In North America, a sideshow is an extra, secondary production associated with a circus, carnival, fair, or other such attraction.
Painting on sideshow truck, firebreather, Florida, 1966
Elly del Sarto, a sideshow performer, in c. 1910
Decaying sideshow advertisement, Florida, 1966