This dissertation contains three chapters, each investigating a question in American economic history. The first chapter is co-authored with Ran Abramitzky, Santiago Perez, and Joseph Price. In this work, we conduct a large-scale digitization of historical college registers, encompassing 2.7 million students at 65 elite US universities. We use this to build the largest and most comprehensive dataset of the socioeconomic backgrounds of students in different US colleges spanning the last 100 years. We find that despite a large increase in the share of lower-income students in the overall college-going population over the last century, there has been virtually no change in the representation of these students at elite private colleges such as Harvard and Yale. In particular, students with parents in the bottom 20% of the income distribution have made up approximately 3-4\% of the student bodies at these institutions throughout the last century. By contrast, there has been a large increase in the share of lower-income students at some elite public schools (such as UC Berkeley and UCLA) and some elite private women's colleges (such as Wellesley and Mount Holyoke). While socioeconomic diversity has not improved at most elite private colleges, there has been an increase in racial and geographic diversity at both private and public elite institutions. In the second chapter, also with Ran Abramitzky, Santiago Perez, and Joseph Price, we augment our novel dataset introduced in Chapter 1 to include the colleges attended by the members of a person's family. We find a striking degree of college-specific intergenerational persistence across virtually all elite institutions in the first half of the 20th century. Between 1915 and 1966, the child of a Harvard alumnus, for example, was approximately 140 times more likely to attend Harvard compared to a child who does not have this parental connection. Combining our historical data with publicly available statistics on the share of alumni children by college, we show that historical legacy rates are similar to those in the modern day (although the degree of persistence does vary by college). Beyond parent-child ties, we find that the younger siblings of alumni had an even greater level of overrepresentation, suggesting that focusing solely on the children of alumni underestimates the extent of familial persistence present at elite universities. As legacy students are more likely to be wealthy, white, and less likely to be Jewish, there are concerns over the inequities that legacy admissions have perpetuated over the course of the last century. The last chapter, co-authored with Natalia Vasilenok, studies the role of location-specific human capital possessed by immigrants and the effect it has on receiving regions. In particular, we study the historical case of late nineteenth and early twentieth century Russian German immigration and the subsequent growth of American wheat farming. We find that this immigrant group possessed specific agricultural knowledge that fundamentally changed what people believed could be cultivated in the newly settled frontier land. We demonstrate that the inflow of Russian German immigrants, through their own farming practices as well as the diffusion of their knowledge to farmers more broadly, caused a shift in agricultural practices from corn to wheat production. Indeed, Russian Germans turned the "Great American Desert" into the "bread basket'' that we know the Great Plains to be today, highlighting the importance of the match quality between immigrants and their receiving locations, as well as the extent to which knowledge diffusion across group boundaries can augment the impact of smaller groups. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]