Circulation has always been a problem for anyone interested in periodicals. Data have remained difficult to obtain and verify. Scholars, for example, often depend on unreliable and anecdotal circulation numbers cited in letters or memoirs. The Circulating American Magazines Project addresses the critical absence of reliable circulation information by digitizing data publishers submitted to the Audit Bureau of Circulations (A.B.C.), building a robust database of circulation data covering the period 1919 to 1972. This data was extracted from the *A.B.C. Blue Book, Periodical Publisher’s Statements*, copies of which are held at a handful of research institutions and the archive of the Alliance of Audited Media. The Co-Directors of this project are Brooks Hefner, Professor of English at James Madison University, and Ed Timke, Instructor in the Department of Cultural Anthropology at Duke University. Hefner and Timke, along with a team of technical experts, have built this site to enable advanced studies of literary modernism and popular literary genres, the history of American publishing, the history and sociology of popular reading and print media in the United States, among many other topics. We hope you find this resource helpful in your study of American periodicals. We welcome any feedback, suggestions, or ideas as our project advances. The OSF home for the site features raw circulation data submitted to the A.B.C. Data is organized by magazine title and is available in CSV and JSON formats. The project [website][1] features visualizations, additional descriptions of the data, and a forum with scholarly discussions of magazine circulation made possible by this data. [1]: https://sites.lib.jmu.edu/circulating/