.. with two new books, each an "appreciation," each under 200 pages.
I think this year's production (add Bonekemper and others) is outstripping demand, rather like the crush of Lewis and Clark books.
If you use the search term popularity tool at Overture, and enter Ulysses S. Grant, Robert E. Lee, and Stonewall Jackson, you'll see what I mean.
The Lee/Grant search ratio now, at about three to one, is way down from five years ago, when it was easily six or seven to one, so things are looking up for Grant in the popular culture.
Nevertheless, you don't want to exhaust an early, tentative public taste in the subject with low-content, high style, non-fiction calories.