Nathaniel Michler (September 13, 1827 - July 17, 1881) was an American military officer and mapmaker who served during the American Civil War. Born in Easton, Pennsylvania, Michler attended West Point, from which he graduated seventh in his class. Commissioned as a 2nd Lieutenant in the Topographical Engineers, Michler participated in the Mexican Boundary Survey from 1851 until 1857, when he was transferred to serve as the chief topographical engineer in surveys for a proposed canal from the Gulf of Darien to the Pacific Ocean from 1858 until 1860. He held the rank of Captain at the outbreak of the American Civil War and served with the Army of the Cumberland from 1861 - 1863, then was transferred to the Army of the Potomac and built defensive works for the Union Army at the Battles of the Wilderness, Spotsylvania, Cold Harbor, and Petersburg. He was promoted to Colonel in August 1864 and brevetted Brigadier General in April 1865. After the war, Michler served as superintendent in the District of Columbia until 1871 and from 1872 to 1875 was chief engineer with the General Commanding Division of the Pacific. He acted as military attaché for the United States Legation in Vienna, Austria from 1878 to 1880.