Social work in the United States emerged out of the work of organized volunteers in the late 19th century. However, the search for professionalization, together with an emphasis on publicly funded social welfare after the 1930s, led social workers to devaluate volunteer activity. Since the 1970s volunteer activity has greatly increased in the United States, and now plays a significant part in American cultural life as well as in the delivery of human services. In recent years volunteerism has been recognized for its demonstrable contribution to the American economy in addition to its fundamental role in a democratic society. Social workers are involved in many ways with volunteers in a multitude of roles and diverse settings and need to understand how to manage and work with a wide range of volunteers.