Great changes took place at Kingston Penitentiary, and in the Canadian federal prison system in general, during the twentieth century. These changes were often the result of dramatic events like prison riots and government investigations, and led to new rehabilitative services and new institutions. But grasping what those changes meant for the incarcerated can sometimes be difficult. This talk follows the life of a single individual, Louis Gallow, who first came to Kingston Penitentiary in 1919 from Hamilton as a teenager, and was paroled for the last time in 1978, to shed light on these changes. Gallow took part in many of the key events of the era, and lived through the professionalization of staff, liberalization of discipline, the creation of a rehabilitative regime, habitual offender designations, and new low security prisons. This talk will discuss how prisoners experienced penal change and thought of reform, from the perspective of someone who spent much of the 20th century behind bars.