Lawrence Fisher and James H. Lorie, and Roger G. Ibbotson and Rex A. Sinquefield have documented annual returns on common stocks since 1926. Prior to 1926, due to the work of the Cowles Commission, annual returns can be extended back to January 1871. This study utilizes Alfred Cowles's reconstruction of common stock returns to provide a comparison between the periods 1871-1925 and 1926-85. A comparable series of annual returns over the complete 115-year period is developed in both nominal and inflation-adjusted terms. The comparison of the two periods suggests that the inflation-adjusted return averages 6.6 percent with similar variability between the two periods. Copyright 1987 by the University of Chicago.