MACKENZIE, AtExANnylt SLIDELL (1803 48). An American naval officer. born in New York City. His family name was Slidell, his brother being the celebrated Senator John Sli dell: but in 1837 lie assumed the name Macken zie in honor of a maternal uncle. Entering the United States Navy as midshipman in 1815, he beeame a lieutenant in 1825 and a commander in 1841. In 1842. while he was in command of the brig Somers, on its return from the West African coast, a conspiracy was thought to have been diseovered among the naval apprentices who con stituted the crew, and :Mackenzie promptly ar rested three men, who on December 1st were hanged from the yardarm in pursuance of the recommendation of a council of officers. One of these men, and apparently the ringleader, was John C. Spencer, the son of the Secretary of War. The affair created wide-spread excitement, Mackenzie being warmly commended in some quarters and bitterly attacked in others. A
court of inquiry, and later a court-martial. com pletely exonerated him from all charges, though the attacks upon him continued and imbittered the whole of his subsequent life. Iii the Mexi can War he was ordnance officer at the siege of Vera Cruz, and commanded the artillery division which stormed Tabasco (June 16, 1847). Ile was a facile and pleasing writer, and published a number of books, including: A Year in. Spain by a Young American (1829): Popular Essays on Naral Subjects (1833) ; The American England (1835) ; Spain Revisited (1836): Life of John Paul Jones (1S41); Life of rommodore O. H. Perry (1841) ; and Life of Commodore Stephen Decatur (in Sparks's American raptly). Consult : The Case of the Somers; De fense of :I. Mackenzie (New York, 1843) ; and, on the other side. James Fenimore Cooper, The Cruise of the Somers (New York, 1844).