William Ellis was born near
Knottsville, Kentucky, on July 24, 1845. He was one of two sons born Luther R. and Mary M. (Kellum) Ellis. Ellis was educated in the common schools until age sixteen. This unit became a part of the
Orphan Brigade. Ellis eventually rose to become a
non-commissioned officer in command of scouts. He served until the end of the war and mustered out on April 21, 1865. After the war, Ellis resumed his studies at Pleasant Valley Cemetery in
Daviess County. To defray the cost of his education, he worked during the summer months. He studied law, supporting himself by serving as principal of
Mount Etna Academy in
Ohio County in 1867 and 1868.
Admitted to the bar in 1868, he attended a course of lectures at
Harvard Law School before commencing practice in
Owensboro in 1870. On October 20, 1871, Ellis married Alice Coffey. Coffey died in 1872, and on November 2, 1876, Ellis married Mattie B. Miller. ==Political career==