See The Diary of James K. Polk (ed. by M. M. Quaife, 4 vol., 1910; abr. in 1 vol. by A. Nevins, 1952); his correspondence, ed. by H. Weaver and P. H. Bergeron (2 vol. 1969–72); biographies by C. G. Sellers, Jr. (2 vol., 1957–66) and C. A. McCoy (1960, repr. 1973); R. W. Merry, A Country of Vast Designs: James K. Polk, the Mexican War, and the Conquest of the American Continent (2009).