Often overlooked, disregarded, or hidden from historical accounts due to its racy connotations, the prostitution industry was one of the most important factors in the development of the American West. The “oldest profession” fueled the economies of camps, towns, and cities as they grew. Sex workers, from common prostitutes to reigning madams such as Anna Wilson, Maggie Wood, and Big Ann Wynne, defied social norms to make sure their hometowns, and they themselves, were successful. Their reasons for entering the life varied, from women who could find no other way to make money to those who desired independence and wealth. In return they were ostracized, criticized, and subject to fines, jail, disease, drug addiction, violence, and unwanted pregnancies. While their success stories are many, others failed in their endeavors, their names buried with them when they died. Behind Brothel Doors chronicles the history of the nineteenth-century sex work industry in the Great Plains states of Kansas, Nebraska, and Oklahoma.