 When Finley, the 10th Surgeon General, was fired after an argument with Secretary of War Edwin M. Stanton, Abraham Lincoln, against Stanton's advice and the normal rules of promotion, named the 34-year-old Hammond to succeed him with the rank of brigadier general.Hammond became Surgeon General of the Army on 25 April 1862, less than a year after rejoining the army.Hammond launched a number of reforms.