On July 22 he was then commissioned as a 2nd lieutenant to fill a vacancy resulting from a casualty during the Battle of Bull Run which was fought the day before.

On May 11, he sent to his brother Dr. Henry E. Turner (1816-1897), who was serving as a contract surgeon at Fort Adams, a short telegram - "Wounded in front of bladder.

Turner (under the sponsorship of his uncle William Greene of East Greenwich, R.I.) chose to remain in Florence for the next thirty years taking a studio there.

Among the more famous of Turner's American works is his bronze Oliver Perry Monument, which was unveiled on 10 September 1885 at the Parade (now known as Eisenhower Park) on Washington Square in Newport, Rhode Island.

During the second decade of the twentieth century, William Greene Turner moved home to Newport from Italy and spent his remaining days doing commissions in the United States.