This study adds to a growing body of research on the contextual determinants of marriage choice and provides new information on ethnic intermarriage in the late 19th century. Census microdata for 66 major cities in 1880 are used to estimate a multilevel model of assortative mating of Irish, German, and British immigrants. Results demonstrate that marital choices made by individuals are significantly affected by the local urban context where they live. In addition, the very large disparity in endogamy between the British and other groups can mainly be attributed to the smaller size of the British population in these cities.