The main case study explored in this book is that of correctional boot camps. Unlike most criminal justice innovations, boot camps received significant attention from policymakers, researchers, the media, and the general public during the past three decades (Kurlychek, 2010). Between 1983 and 2005, some 55 articles discussing correctional boot camps in depth were published in the New York Times and the Washington Post (LexisNexis, 2010; New York Times Archive, 2010). During this same period researchers conducted over 150 studies of correctional boot camps (Wilson et al., 2003). This chapter explains what boot camps are, outlines major evaluations of their effectiveness, and describes their spread across US states.