The first half of the series demonstrated the place of groupwork within the training curricula of probation officers during the early 20th century. Such an emphasis on groupwork in probation during this time transformed the probation from a moral undertaking to a collective casework treatment approach. This article takes up the historical account of groupwork within probation work beginning at the time when the treatment model was coming under attack. It was the focus on groupwork and a more collaborative model that moved probation work towards a more correctional approach. The movement of groupwork to a more central place in probation work was characterized by four features: (1) the emergence of the client as an active agent of change and a continuance of treatment based on a collaborative worker-client relationship; (2) an emphasis on the offense as the focus of probation work; (3) the development of effective probation practices; and (4) increased governance of probation policy and practice and of offenders. The author explores the conflict over whether corrections should be focused on care or control and illustrates how voluntary and stationary day centers were pivotal in the care versus control struggle. The role of groupwork in exposing obscured or neglected needs is discussed and the influence of the cognitive-behavioral model on increasing the governance over both probation work and offenders is reviewed. By the end of the 20th century, groupwork gravitated from a marginalized position within the profession to becoming the center of the effective probation practice. Notes, references