A freak show is an exhibition of biological rarities, referred to as "freaks of nature". Typical features would be physically unusual humans, such as those uncommonly large or small, those with both male and female secondary sexual characteristics, people with other extraordinary diseases and conditions, and performances that are expected to be shocking to the viewers. Heavily tattooed or pierced people have sometimes been seen in freak shows, as have attention-getting physical performers such as fire-eating and sword-swallowing acts.
In 1851 the development of the "set-plate" technique enabled photographers to make many prints from one exposure. Human oddities would have carefully posed photos taken and often order thousands of reproductions. They would sometimes write about themselves on the back of the card bragging about their physical attributes or talents. These "carte de visites" were widely collected by Americans and made quite a bit of money for the "freaks" and the owners of freak shows.
Freaks were often perceived as apprehensive, docile and unhappy with their lot in life. In many cases during the Victorian era, nothing could be further from the truth. Many defended themselves against their managers, talking back and demanding raises. As early as 1851, it had become popular to sell trading cards of popular freaks throughout England and the US. Profits from these images went straight into the pockets of the performers themselves, as opposed to the showmen.
Isaac W. Sprague, the American Human Skeleton, had one of the most successful trading cards. At 5’6”, Sprague weighed only 43 pounds. As he toured with Barnum in the 1860s, he made a good sum of money off of the sale returns from the card. Some of the more willing performers, like Sprague, even penned their own biographies to be published in freak show pamphlets.