William Raymond Lee III was born on August 15, 1807, in Salem, Massachusetts, to William Raymond Lee II and Hannah Tracy. He enrolled at the United States Military Academy at West Point in 1825 and remained until 1829. He left the academy shortly before receiving his military commission and began work as a civil engineer. He married Helen M. Amory in Roxbury, Massachusetts, on July 7, 1842, and they had at least three children: Elizabeth, born around 1843; Arthur, born around 1844; and Robert, born around 1846.
The family lived in Roxbury, and by 1850, he was working as the superintendent of the Boston and Providence Railroad. By 1860, the family owned $20,000 of real estate and $10,000 of personal property. When the Civil War erupted, one early historian noted, he “promptly offered his services to Governor [John] Andrew.” He helped organize the 20th Massachusetts Infantry and received a commission as colonel on July 1, 1861. He was captured in the Battle of Ball’s Bluff on October 21, 1861, and spent the next few months as a prisoner of war. He returned to his regiment in early 1862 and took part in the Seven Days’ Battles and the Battle of Antietam. In late 1862, however, his health began to deteriorate, forcing him to resign from the army on December 17, 1862.
After the war, he received a brevet promotion to brigadier general. Lee settled in Boston, and by 1870, he was working in the U.S. Revenue Office. A decade later, he had resumed work as a civil engineer. He remained in Boston for the rest of his life, and he died there on December 26, 1891.