During the American Civil War, federal authorities sent captured Confederate officers to the military prison on Johnson’s Island in Lake Erie, Ohio. These prisoners came from a narrow demographic; most were Southern, white, upper-class males. They left many documentary accounts of their experiences in the camp, some of which detailed how they used clothing to display both individuality and group identity in their civilian, military, and incarcerated experiences. Twenty years of excavations on Johnson’s Island have resulted in the discovery of at least 1,393 prisoner buttons and numerous other clothing-related artifacts. This study compares the buttons from a single latrine feature and the site as a whole with a unique primary source—a laundry notebook kept by an unknown prisoner—to test the interpretive potential of the historical and archaeological records, and consider what they reveal about prisoners’ clothing. Using data gathered through the end of the 2008 field season, this article examines the biases of both the archaeological evidence and the documentary sources related to changes in prisoner clothing. The results demonstrate how archaeologists can relate isolated privy or latrine features to site-wide patterns over extended periods of time.