ahem , he said , as we in the south refer to it as the battle of sharpsburg ; as i recall , the battle took place in september 1862 the man on the left wearing the derby hat is alan pinkerton , he started the secret service ; of course everyone recognizes ol abe lincoln in the middle who had come to survey the battlefield , and the general on the right , i suppose based on the caption , is general mcclernard ; however , im not too familiar with him .