I’ve uncovered a few more e-books on my travels. They’ve been added to the Library.

John Beatty’s The Citizen Soldier or, Memoirs of a Volunteer – http://www.gutenberg.org/ebooks/20460

Finally, Richard W. Johnson’s A Soldier’s Reminiscences in Peace and War, also via Archive.org, has a handful of personal stories about Lincoln, as well as about several other generals of the war: http://www.archive.org/details/soldiersreminisc00john