Here's another regional small press collection of previously unpublished letters, this time courtesy of the Martha Vineyard's Museum / Historical Society in Edgartown, Massachusetts. The book debuted just a few days ago on July 24 and features the letters of Charles Macreading Vincent, who was 19-years old when he enlisted in 1862. I was not able to determine from the initial story what unit Vincent served in, however according to the online Massachusetts Civil War Research Center, a Charles M. Vincent served in the 40th Massachusetts Infantry.
The book's full title is Your affectionate son, Charlie Mac: Civil War Diaries & Letters by a Soldier from Martha's Vineyard. It runs 292 pages and costs 16.95, which leads me to conclude that it's a paperback. Full online story here.