A large body of research documents the social, economic, and demographic sources of Mexican migration to the United States, but this research tends to use geographically limited survey data, to give little consideration to domestic migration within sending countries as an alternative to international migration, and to focus on men. Since the mid-1980's, however, the regional and rural-urban origins of Mexican emigrants have been diversifying, international and domestic migration flows may have become increasingly interconnected, and women make up a rising proportion of international migrants from Mexico to the United States. This dissertation uses relatively recent, nationally representative Mexican data to analyze the sources of U.S.-bound emigration from Mexico in three main ways. First, I test whether there are rural and urban differences in the correlates of emigration. I find that indeed there are, and that they reflect the articulation between urbanization and economic development in Mexico. Whereas high levels of socioeconomic development within Mexican cities retain emigrants, urban economic development may generate emigration out of neighboring rural places. Second, I document the connection between recent domestic migration and U.S. emigration in Mexico. I find that the relationship varies across Mexico's geography: in rural places and in the historic emigrant-sending region, the two migration flows are still differentiated by the destination-specific role of social networks. However, the two forms of migration are connected in urban areas in the border and center regions. And, third, I evaluate how gender structures the social process of domestic and international migration from Mexico. Migration may be an outcome of socioeconomic development, but social axes of differentiation structure that process above and beyond the economic and demographic forces at play. My research finds that while gender is the form of social difference that most strongly differentiates migration patterns, gendered differences in emigration vary with class, ethnic, and geographic disadvantage. The greatest inequality in emigration exists between those marked by the greatest social disadvantage. / text