Benson, Maxine; Smith, Duane A.; Ubbelohde (December 4, 2015). A Colorado History. The Pruett Series (10th ed.). WestWinds Press An imprint of Graph Arts Books. pp. 145–148. ISBN978-0-87108-323-4. Retrieved February 25, 2017.
Harris, William C. (Winter 2000). "The Hampton Roads Peace Conference: A Final Test of Lincoln's Presidential Leadership". Journal of the Abraham Lincoln Association. 21 (1). Ann Arbor, Michigan: Michigan Publishing, University of Michigan Library: 30–61. hdl:2027/spo.2629860.0021.104.
Summers, Robert. "Abraham Lincoln". Internet Public Library 2 (IPL2). U. Michigan and Drexel U. Archived from the original on October 11, 2011. Retrieved December 9, 2012.
jstor.org
Luthin, Reinhard H. (July 1994). "Abraham Lincoln and the Tariff". American Historical Review. 49 (4): 609–629. doi:10.2307/1850218. JSTOR1850218.
Kinley J. Brauer, "British Mediation and the American Civil War: A Reconsideration," Journal of Southern History, (1972) 38#1 pp. 49–64 in JSTOR
Summers, Robert. "Abraham Lincoln". Internet Public Library 2 (IPL2). U. Michigan and Drexel U. Archived from the original on October 11, 2011. Retrieved December 9, 2012.