Rise to Greatness: Abraham Lincoln and America's Most Perilous Year by Dave Von Drehle

1862 was the year. 1862 was the year our beloved president decided the South was not about to go quietly into their cotton fields and that he needed to get someone in charge who would indeed "go forth and bring him victories." General George McClellan thought he was the man to do just that: Lincoln thought he was a traitor and fired him after the Battle of Antietam, when McClellan failed to finish the day's battlefield horror after Lee retreated to the impassable Potomac.
Lincoln knew his armies had to win to maintain northern support for his effort to restore the integrity of the Union. Fredericksburg under Burnside was a military disaster for the Union at the close of the year, forcing Lincoln to release his revered proclamation of emancipation in order to keep foreign powers from entering the war.
A detailed study of Lincoln, reminding us that our celebrated president was a politician first and humanitarian second.