Davis has written more than 40 books on the American Civil War and other aspects of Southern history. He was twice nominated for a Pulitzer Prize, for Battle of Bull Run and Breckinridge: Statesman, Soldier, Symbol. His work on the Confederacy has also earned him a Jefferson Davis Award and the Jules F. Landry Award for Southern history. His book Lone Star Rising has been called "the best one-volume history of the Texas revolution yet written".

Davis's expertise on Southern history has made him a valued consultant, both for newspaper articles as well as television productions, including the Arts & Entertainment Network/History Channel series "Civil War Journal" and other television productions. He also served as a consultant for the creation of a United States postage stamp of Jefferson Davis and has had input into the formation of the Museum of the Civil War in Petersburg, Virginia.

Mr. Davis holds a Bachelor of Arts and Master of Arts from Sonoma State University. He was awarded the Sonoma State University Distinguished Alumni Award in 1993.

Davis is a past president of the National Historical Society. In 2000, he became a professor at Virginia Tech University, where he also serves as director of programs for the Virginia Center for Civil War Studies.