Connelly was born February 14, 1938, in
Nashville, Tennessee, to Fred Marlin (1909–1983) and Mildred Inez Connelly (1911–1983). As a boy, he visited the Nashville Civil War battlefield. Growing up in the Nashville area gave him a love of country music and spurred his desire to write more about the war in Tennessee. Connelly became one of the most prominent scholars of the war in the western theater in a scholarly field dominated by books about Virginia and its military leaders. Part of his mission to highlight the war in the West was personal. He was frustrated by the fact that his own family's Civil War history was shrouded in rumor and legend. "Scores of personal experiences," he wrote later, "a handful of tales related by an old man, and a shoe box of bullet fragments—such is one family's heritage in the Army of Tennessee." Connelly attended
Rice University, where he obtained his master's degree and Ph.D. He graduated in 1963. His dissertation, done under the supervision of Frank E. Vandiver, was "Metal, Fire and Forge: The Army of Tennessee, 1861-1862." The same year, he published his first book,
Will Success Spoil Jeff Davis? The Last Book about The Civil War, a play on the 1957 film title,
Will Success Spoil Rock Hunter?. Complete with illustrations by Campbell Grant, the book offered a humorous take on Civil War culture and Confederate heritage groups. According to Emory Thomas, publication of the book around the time of the JFK assassination was unfortunate: the book's ironic tone found a small audience in a country grieving over a fallen president. The book is now a collector's item. == Career ==