Freeman, Douglas S. R. E. Lee. A Biography. 4. Bde., Charles Scribner's Sons, New York und London 1934f. online here
Freeman, Douglas S. Lee's Lieutenants. A Study in Command. 3 Bde., Scribners, New York 1942–1944.
Katcher, Philip R. N. & Youens, Michael: The Army of Northern Virginia - Osprey Verlag 1975 Men at Arms Series Book Nr. 37 - ISBN0-85045-210-4
Katcher, Philip R. N. & Volstad Ron: American Civil War Armies 1 - Confederate Troops - Osprey Verlag 1986 Men at Arms Series Book Nr. 170 - ISBN0-85045-679-7
Katcher, Philip R. N. & Volstad Ron: American Civil War Armies 3 - Specialist Troops - Osprey Verlag 1987 Men at Arms Series Book Nr. 179 - ISBN0-85045-722-X
United States. War Dept.: The War of the Rebellion: a Compilation of the Official Records of the Union and Confederate Armies. Govt. Print. Off., Washington 1880–1901, online here.
Young, III, Alfred C. Lee's Army During the Overland Campaign: A Numerical Study (Louisiana State University Press; 2013) 400 pages; argues that Lee's Army was far larger in strength and suffered much higher casualties than previously believed.