In a viral email written to a colleague in 2004, then Maj. Gen. Jim Mattis observed that commanders' relationships are more important than command relationships. This thesis lies at the heart of historian Christian Keller's The Great Partnership. Keller (US Army War College[1]) has written ethnic studies of the Pennsylvania Dutch in the Civil War and is currently working on study examining why the Confederacy failed.

The book comprises six mostly chronological chapters and an appendix. Chapter 1 outlines the Confederates' war plans and orients the reader to present–day concepts of the strategic, operational, and tactical levels of war, with their corresponding echelons of leadership. Keller clarifies how, in the nineteenth century, a leader's presence often blurred the lines between the the tactical and the strategic. He then introduces readers to his protagonists, Robert E. Lee and Thomas "Stonewall" Jackson.

Lee and Jackson's first meaningful collaboration occurred during the Seven Days Campaign. On 23 June 1863, Lee summoned Jackson from the Shenandoah Valley. Jackson, having concluded his successful campaign there earlier in the month, endured a grueling horseback ride to and from the Richmond area to confer with Lee, who had recently assumed battle command of the Army of Northern of Virginia after Gen. Joe Johnston was badly wounded at the Battle of Seven Pines. Jackson, after conferring with Lee, moved his forces to the Peninsula just in time for the Battle of Beaver Dam Creek; throughout the ensuring Seven Days Campaign, he failed to match the aggressive standard he had set earlier in the month in the Valley. Keller, after carefully analyzing Jackson's behavior, attributes his sluggish performance to physical exhaustion. The Lee–Jackson relationship did not get off to a great start, but Lee still saw promise in Jackson. Further campaigning would bear out his faith in Jackson's leadership.

Chapter 2 concerns actions after the Seven Days, including Cedar Mountain, and the origins of the Second Manassas Campaign. Keller uses the war council at Jeffersonton, Virginia, to describe the strengthening ties between Lee and Jackson. Jeffersonton, a small village in northern Culpeper County, a minor crossroads on the way to the Valley, Warrenton, and Culpeper. After skirmishing along the Rappahannock River, Lee and Jackson deliberated in a field near Jeffersonton (24 Aug. 1862). This conference, described in several sources, prompted one of Jackson's bold flank marches, setting up the Army of Northern Virginia for success at Second Manassas, and paving the way for the Maryland Campaign (4–20 Sept. 1862). Keller uses the conference to highlight Jackson's role as trusted adviser to Lee as well as highlighting Lee's use of "mission type orders" to give Jackson broad guidance. This intent based guidance enabled Jackson to execute his march based on his own feel for the terrain and the threat. And too, it jibes with modern military leadership techniques, which specify the "what," not the "how," in commanders' guidance to subordinates. Keller stresses that this change in Lee's issuing of orders reflected his ability to learn from mistakes and improve his communications as a commander.

Chapter 3 concentrates on the winter of 1862–63, which the Army of Northern Virginia spent in its winter encampment along the Rappahannock. It was then that the Lee-Jackson rapport blossomed from a professional into a personal relationship grounded in mutual friendship and their shared Christian faith. Keller points to the increase in Christian revival events in the Army of Northern Virginia camps. Lee and Jackson regularly attended services together, a practice that started after the Second Manassas Campaign. Since Gen. James Longstreet was away on detached service in the Virginia Tidewater and Eastern North Carolina, Jackson became the primary operational lieutenant to Lee during this time.

Chapters 4–5 cover the penultimate Chancellorsville Campaign, where the Lee-Jackson relationship had its greatest success and worst tragedy. Keller again emphasizes an impromptu war council between Lee and Jackson (2 May 1863) to underscore the strength and value of the affiliation. Following the council, Jackson led his force on a flank march and carried the day against Union XI Corps. Tragically, the same evening Jackson is wounded by someone in the North Carolina regiment and died eight days later of an infection following an arm amputation. Lee was personally and professionally devastated. Having lost a, by then, close friend and confidant he had to find a way to reorganize his Army.

Keller devotes an entire chapter to capturing the effect of Jackson's loss on the Confederate populace, as described in contemporary sources from 1863. His research shows that the loss of Stonewall Jackson was a seminal event in Confederate Nation's short history, felt by the common man up to Jefferson Davis.

Chapter 6 concerns the Pennsylvania Campaign, which Lee embarked on twenty-four days after Jackson was killed. Keller shows that Lee's new command team at Gettysburg—the three corps commanders, generals James Longstreet, A.P. Hill, and Richard Ewell—struggled to operate in harmony, while Lee himself failed to give them adequately detailed orders. Keller makes a case for Jackson as a strategic thinker and operational commander, as well as an adviser to Lee. But Jackson's obsession with secrecy and overly detailed orders impeded the development of his subordinates. This was born out by the struggles of Hill and Ewell during the Gettysburg Campaign.

Keller closes with an appendix identifying lessons today's leaders might draw from the Lee-Jackson exemplar. He stresses the need of senior commanders to have trusted advisers and the value of friendship between leaders.

The Great Partnership is a salutary addition to the scholarship on Civil War leadership and an engaging operational/strategic history of the Army of Northern Virginia in the critical period between the Seven Days and Gettysburg.