National service and volunteerism enjoy a rich history in the United States and an emergent future in other parts of the world. However, there remains relatively scant evidence of overall impact of national service programs and volunteer effectiveness. This condition continues to threaten national service and volunteer programs with the risk of defunding and/or the risk of not investing sufficiently from the start. This book brings together a selection of diverse chapters written by a combination of academicians, students, and practitioners from three countries and across multiple states in the United States. Each chapter approaches its topic uniquely but links with all others in identifying the impacts of service and volunteerism for volunteers, for beneficiaries of service, for the institution of volunteering, and/or for whole communities. The book is divided in five sections: (1) developing volunteer initiatives to achieve impact, (2) impact for and by youth volunteers, (3) impact in social or policy areas, specifically economy and financial success, education, and emergency response, (4) international perspectives with focus on Chile, Venezuela, the United Kingdom, and the post-communist states of Lithuania and Romania, and (5) conclusion with summary and suggestions for future research and practice.