Adjutant-General of the 3d Army Corps of the Army of the Potomac, commanded by General Heintzelman; participated in the battles of the Peninsular Campaign; subsequently served with General Banks.

Was appointed Assistant Surgeon of the U. S. Army in 1847, and served with the Army of Occupation at Vera Cruz and Toluca, Mexico, and at Fort Crawford, Fort Leavenworth, in Oregon, Washington Territory, and Texas until his resignation in 1855. In the Civil War he was appointed Lieutenant-Colonel of a regiment attached to Sickles' Brigade, but was soon compelled, by failing health, to resign. He was appointed Surgeon of the United States Volunteers and placed in charge of camp hospitals in the Army of the Potomac and subsequently served with General Gordon Granger, in the West. He was mustered out of service in 1865, after receiving the Brevet of Colonel for faithful and meritorious services.

During the Draft Riots at New York City he did heroic service for which he received an autograph letter from President Lincoln, thanking him for the eminent services rendered by him to our country during those days of darkness. Subsequently, he devoted himself to journalism, editing several leading German newspapers.

Was mustered in service as Captain; he rose to the rank of Lieutenant-Colonel. His term of service expiring a few days prior to the battle of Chancellorville, May 2, 1863, he expressed a desire to remain at the front and during that terrible struggle his foot was shattered by a cannon ball; was taken to Washington, where he died shortly after. President Lincoln visited him at his bedside, and brought his commission promoting him to the rank of Brigadier-General.