American Civil War A Group of Federal Officers Behind the Line A typical group of officers of the victorius Federal . Standing is Colnel Ulric Dahlgren , on the staff of General Meade . On left of picture , holding ' the art of war ' is Major Ludlow , commander of coloured brigade . In straw hat is Colonel Dickinson , aide to General Hooker , and kneeling net to him Count Zeppelin , a Prussian officer on visit to the front . On the right is a visiting Swedish officer . Many of the best officers in Federal Army came from a civilian life .