The eleven papers collected in this volume appeared in the Bulletin of the AMS during the years 1955 to 1984 and share the theme of the representation theory of locally compact groups and its numerous applications. The papers provide a glimpse at the historical development of a subject which has expanded into many areas of mathematics during the past forty years. In addition, this volume provides easy access to a useful set of references. Chronicling some of the most important developments by some of the field's major figures, this book will appeal to specialists in representation theory as well as to researchers in those areas of mathematics in which representation theory plays an important role.