The collection largely consists of correspondence between Carto and others. The collection came to Spencer Research Library in chronological groupings, which Spencer staff have maintained; some correspondents had been separated by Carto or somebody else prior to coming to Spencer, and those separations have also been maintained, with these individuals appearing at the end of the correspondence series.

Frequent or notable correspondents include the American Progress Foundation (Willis E. Stone), American Council of Christian Laymen (Verne P. Kaub), America First!, Association of Citizen's Councils of Mississippi, The National Segregation Party, National States' Rights Party (Ed Fields), America Plus, the Constitution Party in California, Nationalist Conservative Party, New Foundations, The Virginian (William Scott Stephenson), Christian Educational Association, American Heritage Protective Committee, Abraham Lincoln Republican Club, United White Party (Matt Koehl), Christian Crusade, the National Socialist White People's Party, We the People (Harry T. Everingham), the Freedom School (Robert LeFevre), American Flag Committee, Trade Policy Congress, John Birch Society (Robert Welch), Noontide Press, Western Destiny, Church of the Creator (Ben Klassen), Youth Action, Christian-Patriots Defense League, Institute for Historical Review, and the Congress of Freedom.

Also in the collection are some reference materials, newspaper clippings, and other items of interest to Carto and related to his political philosophies and affiliations.