This book is the first to chronicle the story of Housing First (HF), a paradigm-shifting evidence-based approach to ending homelessness that began in New York City in 1992 and rapidly spread to other cities nationally and internationally. The authors report on the rise of a 'homeless industry' of shelters and transitional housing programs that the HF approach directly challenged by rejecting the usual demands of treatment, sobriety and housing readiness. Based upon principles of consumer choice, harm reduction and immediate access to permanent independent housing in the community, HF was initially greeted with skepticism and resistance from the 'industry'. However, rigorous experiments testing HF against 'usual care' produced consistent findings that the approach produced greater housing stability, lower use of drugs, and alcohol and cost savings. This evidence base, in conjunction with media accounts of HF's success, led to widespread adoption in the U.S., Canada, Western Europe, and Australia. The book traces the history of homelessness and the rapid growth of the publically funded homeless industry, an amalgam of religious and philanthropic organizations, advocacy groups, and non-profits that were insufficient to stem the tide of homelessness resulting from dramatic reductions in affordable housing in the 1980s and continuing to the present day. The authors summarize research findings on HF and include a chapter of personal stories of individuals who have experienced HF. Unique to this book is the participation of the founder of HF (Tsemberis) and well-known research on HF by the co-authors (Padgett and Henwood). Also unique is the deployment of theories-organizational, institutional and implementation-to conceptually frame the rise of HF and its wide adoption as well as the resistance that arose in some places. Highly readable yet informative and scholarly, this book addresses wider issues of innovation and systems change in social and human services.