William Emery Merrill (October 11, 1837 - December 14, 1891) was an American engineer and soldier. Born at Fort Howard, Wisconsin, Merrill graduated first in his class at the United States Military Academy at West Point i n1859 and served as an assistant professor of engineering at the Academy from September 1860 until July 1861. During the American Civil War, Merrill served as assistant engineer in the Army of the Potomac during the Peninsular Campaign and in the Northern Virginia Campaign. From July 1864 until September 1865, Wright commanded a regiment of veteran volunteer engineers. After the war, from 1867 until 1870, Wright served as chief engineer on the staff of General William T. Sherman and, following his departure from General Sherman's staff, working on engineering project for the government until his death from heart failure in December 1891.