Turner had become a free man in 1843 when his mother was freed. He was then educated in St. Louis schools. He went on to study at Oberlin College in Ohio. Turner became secretary of the Missouri Equal Rights League in 1865 and traveled extensively in Southeast Missouri, advocating education and voting rights for black men. As a result of these efforts, Turner is credited with delivering 20,000 votes to the Republican Party in the 1870 election. In later years, Turner became well known as an attorney in the fight to secure black claims for government benefits and as an advocate for blacks with land and oil claims in the Oklahoma Indian Territory. He is buried in the Father Dickson cemetery in Crestwood.