For Want of a Nail ... includes a bibliography on pages 411-426 that lists 475 works (three written in Spanish, the rest in English), that served as Robert Sobel's source material. Rather than being grouped by categories, the works in the bibliography are listed alphabetically by author.
The earliest works listed are the three volumes of Sir John Dickinson's The Late Rebellion, published in Philadelphia in 1784. The latest works cited were published in 1971, the year the book was written. They include John Flaherty's The Carminales Legacy: Mexico's Edison, Max Josephson's The End of the Western Era, Hubert Lodge's Men for their Age: The Hemingway and Merriman Administrations, Frank Rusk's A Statistical Analysis of the 1968 C.N.A. Election, Stanley Tulin's The Kramer Associates: The Benedict Years, and Kenneth Zarb's Inside the U.S.M.: Mercator's Folly.
In his critique of Nail, Frank Dana mentions several important works that Sobel failed to including in his bibliography, including Lawrence Gilman's Duel for a Continent (Mexico City, 1959), Jaime Milton's The Manumission Years: Emiliano Calles and the People (Mexico City, 1966), Henry Tracy's The United States of Mexico and the Confederation of North America (New York, 1969), and Oscar Jamison's The Struggle for Liberty: Henry, Adams, and the American Rebellion (Melbourne, 1969).