Newspaper clippings, correspondence, and literary productions relating to political conditions in Mexico during the revolutionary period and to Mexico's relationship with the United States and U.S. oil companies operating in Mexico. Narrower topics include revolutionary disturbances in Mexico; the situation of American residents of Mexico, described in materials of the American Association of Mexico and other groups representing Americans in Mexico; the 1914 American occupation of Veracruz; and Buckley's expulsion from Mexico. Clippings, which form the bulk of the papers, are from both Mexican and American newspapers; some are in scrapbooks.

Correspondence pertains to Buckley's professional and personal business and includes reports from field agents. Literary productions include transcriptions of newspaper texts as well as reports, statements, speeches, notes, and interviews reflecting Buckley's opinion of events in Mexico. Materials dating from after Buckley's residence in Mexico are few.