--- - |2 Early work in feminist theory hypothesized that differences in women and men's social and institutional roles might be reflected in the ways they participate in the political sphere. However, past empirical research has found scant evidence of a gender gap in the participatory strategies or motivations of women and men who become active in politics. But significantly less is known about the gender gap among a more select and increasingly significant player in American politics—political donors. In this article, we utilize a novel big data set—called the Longitudinal Elite Contributor Database (LECD)—that contains the population of all itemized donations made in federal elections between 1980 and 2008. Using this novel big data set supplemented with Social Security Administration (SSA) data on the gender of first names, we provide original estimates of the long‐term evolution of gender representation in the donor pool, vis‐à‐vis when, how often, and to whom affluent men and women have made political contributions over nearly 30 years. We find that large and persistent gendered inequalities of political voice continue to characterize this significant form of political influence. We theorize the potential implications of these findings for the representation of women's interests in the political sphere. - 'Sociological Forum, Volume 33, Issue 3, Page 805-825, September 2018. '