I really can't recommend these books strongly enough. They read like the second coming of Bruce Catton out of S.M. Stirling, or like Michael Shaara's The Killer Angels, if you've read that - and if you haven't, why not?
We're used to regarding Grant and Lee and Lincoln as these huge iconic figures, but Forstchen and Gingrich bring them to life without feeling the need to dwell excessively on their failings. We are given a wonderful view of their interior lives, the things that drove them and how they rose above their human frailties to become the heroes they were. We're also given good looks at minor figures - sergeants and lieutenants, lesser leaders like Herman Haupt, and Jim, the White House butler who plants an interesting seed in the mind of President Lincoln.
These books will appeal to people interested in the Civil War and to alternate-history fans, though I suspect some of the latter will be disappointed that this branch off the Main Line doesn't go as far afield as, say, Ward Moore's Bring The Jubilee.
I was going to do a massive year in review post, but there's really no time for that since I'm being hired to play taxi for P, and I want some solid food in my stomach before I go off to the work (and party) of the day.