The Fiery Trial won the Pulitzer, Bancroft and Lincoln prizes, and was written by the former president of the American Historical Association and doyen of the time period, Eric Foner. It includes pre-war biography for context but it is about how Lincoln adapted to the real experience of wielding power. Anything by Foner will be very, very good so look through his catalogue to see if anything else he has written stands out to you.

Another great choice is any of James McPherson’s books on Lincoln, such as Tried by War: Abraham Lincoln as Commander in Chief. He has a similarly impressive list of awards, and is widely regarded with Foner as one of the greatest historians on this period. His book The Battle Cry of Freedom still stands as an incredible macro-view of the structural forces which shaped the Civil War Era.