Born near Guntown, Itawamba County, Mississippi, Cornelius H. Hankins was the sixth of eight children of Reverend Edward Locke Hankins and Annie Mary McFadden Hankins. He contracted smallpox after his mother cared for Confederate soldiers. As a result, he was deaf until he was eight years old and had to be tutored at home.
In 1883 Hankins studied with Nashville professor Edwin M. Gardner and taught art at Mrs. Creek's (or Miss Clark's) Select School for Girls in Eagleville in Rutherford County. Later he studied in St. Louis with Robert Henri, leader of the Ashcan School, and with William Merritt Chase in New York.
From 1894 to 1899 Hankins worked and taught in Richmond, Virginia, where he exhibited at the first three exhibitions of the Art Club of Richmond. In 1898 he married Sophia Maude McGehee (1875-1968), an artist who specialized in china painting, miniatures, and watercolors. During this period, Hankins was commissioned to paint posthumous portraits of twelve Confederate generals from photographs. In 1901 the Tennessee General Assembly commissioned him to paint a portrait of Robert E. Lee.
About 1904 Hankins and his wife moved to Nashville, where he was first associated with George W. Chambers of the Nashville School of Art. Hankins painted still lifes and landscapes, especially Tennessee wheat fields. But his bread and butter came from portraits, and he painted over a thousand of them, fifteen bust portraits for the Shelby County Court House alone. Hankins painted a number of prominent Tennesseans including Confederate Generals Benjamin F. Cheatham and Nathan Bedford Forrest, Admiral Albert Gleaves, Senator William B. Bate, and Governors Albert Roberts and Benton McMillin. At the time of his death, nine of his portraits were hanging in the Tennessee State Capitol, six in the Alabama State Capitol, two in the Mississippi State Capitol, and one in the Louisiana State Capitol.