Rising intermarriage rates among American Jews have sparked intense debate about religious continuity, yet little research has examined the growing phenomenon of conversion to Judaism through marriage. Analysis of nearly 400 convert records and over 200 questionnaire responses reveals a predominantly female (66%), highly educated cohort who convert young (median age 24.4) and overwhelmingly in connection with Jewish marriage (93%). Data collected in 1978 across the Midwest and New England, including interviews and participant observation in conversion classes, shows that most converts come from marginally religious Christian backgrounds - 48% Catholic and 39% Protestant. While marriage serves as the catalyst, converts consistently cite deeper motivations: a perceived superiority of Judaism over their former faith and desire for religious unity in child-rearing. Jewish communal participation falls into seven distinct categories, ranging from "Integral Converts" (12%) who embrace intensive Jewish life to "Non-Jews" (7%) who ultimately reject their conversion, with 55% maintaining active or potentially active Jewish engagement. Converts primarily conceptualize Judaism through a religious rather than ethnic lens, using ritual observance to authenticate their Jewish identity. The findings demonstrate that conversion to Judaism involves complex identity transformation, with converts achieving varied levels of integration into American Jewish communal life while maintaining commitment levels generally comparable to born Jews.