He was promoted to captain in 1778 and wounded "several" more times during the war. He penned a series of letters to Friedrich Christian Arnold von Jungkenn, the Hesse-Kassel Minister of State. These missives survived and provide an important account of the war.[2] On 18 January 1778 he wrote that the Americans were not, "to be despised", and that it only, "requires Time and good leadership to make them formidable".[3] He also described his activities in detail during the Siege of Charleston in 1780.