A hundred years ago, Agassiz propounded his glacial theory. Seventy-five years ago this theory had widely proved its truth, and glacial geology can be said to have been established as a science. Fifty years ago The Geological Society of America was founded. Thus the Society has witnessed half the time since Agassiz’ great discovery and two-thirds of the history of glacial geology. It has not merely witnessed the gains made during those passing years; it has played an active part in the development of glacial study. Nine of the 40 scientific communications published in Volume 1 of the Bulletin are on glacial subjects, and every meeting of the Society has had glacial discussions. During this time glacial geology has become an important discipline, making use of geophysical and microscopic methods and furnishing important data toward the solution of some of geology’s most fundamental problems. At this milestone in the history of the Society—equally a milestone in the history of geologic research in America—it is appropriate that we review our glacial accomplishments, take stock of our present position, and examine our program for the future in this as in other fields. For convenience in treatment, the field of glacial geology is subdivided into several sections.