Harris's With Charity for All: Lincoln and the Restoration of the Union came in second place for the Lincoln Prize in 1998.[5] He then received the Lincoln Diploma of Honor from the Lincoln Memorial University in 2003.
In 2008, Harris's writing was also awarded Henry Adams Prize offered by the Society for History in the Federal Government with his book Lincoln's Rise to the Presidency[6][7]
Most notably, Harris was awarded the Gilder Lehrman Lincoln Prize in 2012.[8]
Presidential Reconstruction in Mississippi. Baton Rouge, Louisiana State University [1967]. OCLC647759
The Day of the Carpetbagger: Republican Reconstruction in Mississippi. Baton Rouge: Louisiana State University Press, 1979. ISBN9780807103661. OCLC3915482
William Woods Holden: firebrand of North Carolina politics. Baton Rouge: Louisiana State University Press, 1987. ISBN9780807113257. OCLC15109349
With Charity for All: Lincoln and the Restoration of the Union. Lexington, Ky.: University Press of Kentucky, 1997. ISBN9780813109718. OCLC35574529
Lincoln's Last Months. Cambridge, Mass.: Belknap Press of Harvard University Press, 2004. ISBN9780674011991. OCLC52858521
Two Against Lincoln: Reverdy Johnson and Horatio Seymour, Champions of the Loyal Opposition. Lawrence, Kan.: University Press of Kansas, 2017. ISBN978-0700624126. OCLC963736321