John Esten Cooke, Robert E. Lee (2017). “General Robert E. Lee: The True Story of the Infamous “Marble Man”: The Life & Legacy of Robert E. Lee, Including & Personal Writings, Speeches and Orders”, p.42, Madison & Adams
"An Additional Number of Letters to the Republican". Letters by the Federal Farmer (pseudonym of Richard Henry Lee), Letter XVIII, teachingamericanhistory.org. January 25, 1988.
Edward Gibbon, Francis Parkman, William H. Prescott, Theodore Roosevelt (2012). “The Modern Library Essential World History 4-Book Bundle: The Decline and Fall of the Roman Empire (Abridged); Montcalm and Wolfe; History of the Conquest of Mexico; The Naval War of 1812”, p.237, Modern Library