This paper constitutes primarily an updating of the material in the 1940 Population Census special report prepared by Alba M. Edwards and entitled Comparative Occupation Statistics in the United States: 1870-1940 (U.S. Government Printing Office, 1943). The process of updating involved bringing together certain of the separate series developed by Dr. Edwards, preparing a number of new estimates to fill gaps, and adjusting the appropriate figures to conform to the definitions of the 1950 occupational classification system. Except where there was firm statistical evidence to support a change, Dr. Edwards’ basic assumptions and estimates were utilized throughout. Perhaps the prime example is the farm worker figures. Other investigators have prepared substantially different estimates of the adjustments necessary to compensate for the “overstatement” in the 1910 enumeration and the “understatement” in the 1920 enumeration. In the absence of convincing evidence that any one set of estimates was truly superior, Dr. Edwards’ adjustment have been used here.