Nat S. Floyd was born around 1834 in Kentucky. By 1860, he was working as a farmer in Dallas County, Texas, and he owned $4,200 of real estate and $540 of personal property.
He enlisted in the Confederate army on January 20, 1862, and he mustered in as a private in Company E of the 18th Texas Cavalry. He was promoted to sergeant on May 26, 1862.
Union forces captured him at Fort Hindman, Arkansas, on January 11, 1863, and imprisoned him at Camp Douglas near Chicago, Illinois. He was released on April 3, 1863, and he died of pneumonia in Petersburg, Virginia, on April 18, 1863.