Treat’em Tough”: The Militarization of the New York Police Department, 1926-1962 This study examines the linkage between the professionalization and militarization of the New York Police Department between the mid-1920s and the early 1960s. In doing so, it joins a growing body of scholarship examining the rapid expansion of the American carceral system and the vast growth in police power undergirding it over the past sixty years. Scholars treat these twin developments as products of national policies such as Lyndon Johnson’s War on Crime. This dissertation will challenge that dominant narrative by linking earlier shifts in municipal policing to the subsequent explosion of national ‘tough-on-crime’ policies that fueled mass incarceration.