RONCKENDORFF, William, naval officer, born in Philadelphia, Pennsylvania, 9 November, 1812. He entered the navy as midshipman, 17 February, 1832, became passed midshipman, 23 June, 1838, was commissioned lieutenant, 28 June, 1843, and in June, 1845. was bearer of despatches to the commander-in-chief of the Pacific squadron, with which he served during the Mexican war. He was in the " Savannah" at the capture and occupation of Monterey and points on the coast of California, and returned to New York in September, 1847. He commanded the steamer " M. W. Chapin " in the Paraguay expedition of 1859 and on coast survey duty in 1860, was commissioned commander, 29 June, 1861, and had charge of the steamer "Water Witch" from 1 March till 12 October, 1861, in the Gulf squadron. On 27 December, 1861, he took command of the steamer "San Jacinto," with which he was present in Hampton Roads to fight the " Merrimac," and participated in the attack on Sewell's Point, 15 May, 1862, and in the capture of Norfolk on 18 May He was in the " Ticonderoga," searching for privateers in 1863, and in February, 1864, he commanded the monitor "Monadnoek " in operations in James river until the evacuation of Richmond, when he cruised to Havana in search of the "Stonewall."

In July, 1865, he was transferred to the monitor "Tonawanda." He was commissioned captain, 27 Sept, 1866, and was at Philadelphia until 1 October, 1870, when he took charge of the iron-clads at New Orleans until 8 April, 1872. He commanded the steamer "Canandaigua," of the North Atlantic squadron, in 1872-'3, was promoted to commodore, 12 September, 1874, and was placed on the retired list on 9 November, 1874, by reason of his age.