This history covers the first forty years of Russell Sage Foundation's efforts toward "the improvement of social and living conditions in the United States of America." It records the things that were done, both as direct work and through grants, with considerable attention to the social situation which made them seen necessary or desirable. It is of value not only to those interested in the operation of the Russell Sage Foundation or other foundatons, but for the light it throws upon the origins and development of a wide variety of movements in the borad field of social science.