The M. Watt Espy papers chronicle the extensive research efforts that led to the creation of the Capital Punishment Research Project and the database known as the Espy File. Espy spent three decades gathering and indexing documentation of legal executions in the United States. His papers contain both primary and secondary sources used to catalog thousands of instances of capital punishment in the United States and its territories since the 1600s. The collection includes material from corrections records, newspapers, county histories, legal proceedings, and books. In addition to the records pertaining specifically to the death penalty, there is also a selection of magazines collected by Espy that cover true crime stories as well as life in the American Old West.