This paper estimates historical measures of equality in the distribution of education in the United States by age group and sex. Using educational attainment data for the population, the EduGini measure indicates that educational inequality in the U.S. declined significantly between 1950 and 2009. Reductions in educational inequality were more profound during the first three decades of the study than the last three, with the degree of inequality remaining relatively constant since the early 1990s. Educational inequality has historically been higher among males than females, but recently the gap has narrowed substantially. Older age groups have experienced greater declines in educational inequality compared to younger age groups. Research extensions of the data presented in this paper are discussed. Appended are: (1) Full Methodology; (2) EduGini by Year, Age Group; (3) Male EduGini by Year, Age Group; and (4) Female EduGini by Year, Age Group. (Contains 5 figures, 3 tables, 20 footnotes.)