Lieutenant-Colonel [James H.] Wilson of my staff was sent to Helena, Arkansas, to examine and open a way through to Moon Lake and the Yazoo Pass if possible. Formerly there was a route by way of an inlet from the Mississippi River to Moon Lake, a mile east of the river, thence east through Yazoo Pass to Coldwater, along the latter to Tallahatchie, which joins the Yallabusha about two hundred and fifty miles below Moon Lake and forms the Yazoo River.This is much easier to follow on a good map, such as the map that Lieutenant-Colonel Wilson produced.
To guide me through the hard terrain of Grant's Memoirs, I relied on the National Geographic Atlas of the Civil War: A Comprehensive Guide to the Tactics and Terrain of Battle (256 pp., $40). The atlas begins with an essay on the importance of cartography in the Civil War. "Southerners," the essay concludes, "had the advantage of fighting this war largely on their own soil, but that was offset as the conflict progressed by the superior mapmaking resources of the North." The Union armies had to penetrate deep into Confederate territory, and face an opponent who was familiar with the lay of the land, so mapmakers like Wilson were essential to the Union's success. And the maps they made continue to be essential for those attempting to follow the movements of the armies a century and a half later.
The National Geographic Atlas is full of colorful, easy-to-read large format maps, most of them either contemporary or produced soon after the war. Some of the most remarkable maps are those produced by Robert Knox Sneden, a Union soldier, mapmaker and painter who produced a remarkable illustrated diary, much of it composed secretly while he was being held in Andersonville Prison. The diary was rediscovered in 1994, and currently resides in the Virginia Historical Society. Go here to see Sneden's map of the investment of Petersburg, one of the maps included in the atlas.
Another atlas that I occasionally consulted was Aaron Sheehan-Dean's Oxford Concise Historical Atlas of the U.S. Civil War (112 pp., $25). This is a small paperback book with maps produced by the author using GIS and Adobe Illustrator. For a reader attempting to follow the movements of Grant's army, the Oxford atlas falls short. Its strength lies in its inclusion of data maps that illustrate census data such as agricultural productivity in the United States at the outbreak of the Civil War. These maps are often surprising. For example, the map of agricultural productivity shows that, although the South is generally thought of as agricultural and the North as industrial, the North actually generated more agricultural wealth in 1860. Wheat produced by free labor was more lucrative than cotton produced by slaves, and the North produced more commodities for home consumption, while the South relied too heavily on staple crops for export. These maps, and the accompanying text, are extremely useful in providing some socioeconomic context for the war, but the actual battle maps are disappointingly lacking in detail.
For the neophyte like me, I would recommend the National Geographic Atlas. It's beautifully illustrated, easy to read, admirably comprehensive and, at $40, reasonably priced for such a large and well-illustrated book.