Alexander Winchell was born in Dutchess County, New York, December 31, 1824. In 1847 he was graduated Bachelor of Arts from Wesleyan University, having defrayed the cost of his college education by teaching school. He now entered at once upon his career as a teacher of science. He was employed one year at Pennington Seminary, New Jersey, two years at Amenia Seminary, New York, and for the three following years in Alabama.

In 1853 he was appointed to the chair of Physics and Civil Engineering in the University of Michigan. In 1855 he was transferred to the chair of Geology, Zoology, and Botany, which he continued to hold until 1873. He then resigned to accept the chancellorship of Syracuse University, but performed the duties of that office for only a year and a half.

The financial depression of the times rendered the position peculiarly trying, while executive duties interfered seriously with his favorite studies. He accordingly resigned the chancellorship and accepted the professorship of Geology. For three years, 1875-1878, he divided his time as professor between Syracuse University and Vanderbilt University. In 1879 he was called back to the University of Michigan as Professor of Geology and Paleontology, and here he passed the remaining years of his life.

He was director of the Geological Survey of Michigan in 1859, and again from 1869 to 1871. He prepared and published a geological map of the State, which he continued to revise, and finally finished in 1889, for the National Geological Survey. He rendered valuable service to the State by his study of soils and mineral fertilizers, and by directing the opening of salt deposits. In 1886-1887 he was engaged in the geological survey of Minnesota. His most noteworthy contributions to science were the establishment of the Marshall group of strata, and the original description of three hundred and eight new species of fossils, seventy-eight of which he described in connection with other geologists.

His principal publications are the following: "Sketches of Creation" (1870); "A Geological Chart" (1870); "Michigan Geologically Considered " (1873); "The Geology of the Stars" (1874); "The Doctrine of Evolution" (1874); "Reconciliation of Science and Religion" (1877 ); "Pre-Adamites, or a Demonstration of the Existence of Men before Adam " (1880); "Sparks from a Geologist's Hammer" (1881); "World Life, or Comparative Geology" (1883); "Geological Excursions, or the Rudiments of Geology for Young Learners" (1884); "Geological Studies, or Elements of Geology" (1886); and "Walks and Talks in the Geological Field" (1886). He led an active religious life as a member of the Methodist Episcopal Church. In 1867 Wesleyan University conferred upon him the degree of Doctor of Laws. He died at Ann Arbor, February 19, 1891.