Discussed:
Jeffry Wert has written a number of good books on various Civil War topics; in particular I am familiar with his biography of James Longstreet which is quite good.
In A Glorious Army he takes on one of the most written about figures of the Civil War, Robert E. Lee. His focus is Lee's impact on the Army of Northern Virginia from the point where Lee took command during the Peninsula Campaign, through the defeat at Gettysburg. This period covers one year, one month, and a couple of days, from June 1st, 1862 to July 4th, 1863. It is quite astonishing to realize that the period which made Lee's legend was so short. In this time, the Army of Northern Virginia fought major battles: Mechanicsville, Seven Pines, Gaines Mill, Glendale, Malvern Hill, Second Manassas, Antietam, Fredericksburg, Chancellorsville, and finally Gettysburg.
One might wonder why Lee is being revisited yet again. It turns out that it is worthwhile; there has been a significant movement in Civil War scholarship in recent years, exemplified by Joseph Harsh's important studies of Lee's campaigns in 1862 (Confederate Tide Rising and Taken at the Flood.) Much reassessment has taken place; while Freeman's massive studies of Lee (R. E. Lee and Lee's Lieutenants are still respected, certainly, there is recognition that Freeman was deeply rooted in the Lost Cause Mythology and this colors his perspective. The reexamination has been refreshing, and much of the new scholarship has been outstanding, turning up things that have been overlooked for 100 years or more.
Wert chooses to focus on Lee and his relationship with the Army of Northern Virginia, how Lee influenced it and used it during its period of greatest success. He is attentive to modern work such as that of Harsh, although occasionally he still references things that modern scholarship takes issue with (e.g., Henry Heth's claim that his division was heading to Gettysburg to look for a cache of shoes.) These are minor issues that do not detract from Wert's overall thesis.
Wert's assessments of Lee and his immediate subordinates (Longstreet, Jackson, Stuart, Ewell, A.P. Hill, etc.) seem fair. I wouldn't come to this book looking for an assessment of George McClellan, but that's not really what it's about. The things Wert is trying to do in this book, he does well.