Contemporary trends in low fertility can in part be explained by increasing incentives to invest in offspring’s embodied capital over offspring quantity in environments where education is a salient source of social mobility. However, studies on this subject often rely on homogenous populations, missing out on the opportunity to investigate how this relationship is impacted by structural factors that asymmetrically allocate economic opportunities between members of different groups. Using General Social Survey data from the US, I examine changes in the relationship between number of siblings and college attendance for White and Black respondents throughout the 1900s. Results showed that White individuals from larger families had a lower chance of completing at least four years of college education than individuals from smaller families, while the likelihood for Black individuals was more uniform across family sizes. Though results were not significant for every cohort, racial difference was generally larger in cohorts born in the early 1900s and converged in the later part of the century. These results explain variations in the timing of demographic transitions within subpopulations of a nation and suggest that the benefits of decreasing family size on educational outcomes may be conditional on the specific economic opportunities afforded to a family.