Oates (December 1980), The Slaves Freed, American Heritage Magazine Oates, Stephen B. (December 1980). "The Slaves Freed". American Heritage Magazine. Vol. 32, no. 1. Retrieved September 25, 2011.
Reynolds, Robert L. (December 1960). "Seward's Wise Folly". American Heritage. 12 (1). Retrieved November 29, 2011.
Charles Sumner, Freedom National; Slavery Sectional: Speech of Hon. Charles Sumner… (Boston: Ticknor, Reed and Fields, 1852), available online, accessed June 24, 2011
Corning, Amos Elwood (1918). Hamilton Fish. Lamere Pub. Co. pp. 59–84.
Pfau 2003, p. 393. Pfau, Michael William (2003). "Time, Tropes, And Textuality: Reading Republicanism In Charles Sumner's 'Crime Against Kansas'". Rhetoric & Public Affairs. 6 (3): 385–413. doi:10.1353/rap.2003.0070. S2CID144786197.
"Charles Sumner." Dictionary of American Biography Base Set. American Council of Learned Societies, 1928–1936. Farmington Hills, MI: Gale, 2009. available online
The relationship between Brooks and Butler is often reported inaccurately. "In reality, Brooks's father Whitfield Brooks, and Andrew Butler were first cousins." Mathis, Robert Neil (October 1978). "Preston Smith Brooks: The Man and His Image". The South Carolina Historical Magazine. 79 (4): 296–310. JSTOR27567525.
Stanley Coben, "Northeastern Business and Radical Reconstruction: A Re-examination", Mississippi Valley Historical Review Vol. 46, No. 1 (Jun. 1959), pp. 67–90 in JSTOR
Gilbert Osofsky, "Cardboard Yankee: How Not to Study the Mind of Charles Sumner", Reviews in American History Vol. 1, No. 4 (Dec. 1973), pp. 595–606 in JSTOR quotes are in Osofsky's words on pp. 595, 596
Pfau 2003, p. 393. Pfau, Michael William (2003). "Time, Tropes, And Textuality: Reading Republicanism In Charles Sumner's 'Crime Against Kansas'". Rhetoric & Public Affairs. 6 (3): 385–413. doi:10.1353/rap.2003.0070. S2CID144786197.