John Jacob Astor, Jr., grandson of the fur trader who was the first American to accumulate a great fortune, was eager to demonstrate his patriotism. He was, however, less than enthusiastic about signing up for three years of military service. Hence he negotiated a deal whereby he became a volunteer aide-de-camp to Maj. General George B. McClellan.
Colonel Aster took up his duties in November 1861 and remained with the Army of the Potomac for eight months. There’s no record that he ever carried a musket or was exposed to confederate fire, but in 1865 he was awarded a brevet as brigadier general "for services rendered during the Peninsular Campaign.”