Smith Daniels was born on November 25, 1836, in Miami County, Ohio, to Smith and Martha Daniels. His father was a farmer who owned $2,500 of real estate and $500 of personal property by 1860. Daniels grew up and attended school in Union, Ohio, before beginning work as a farm laborer. He married Clarisa Fie on July 21, 1861, and their daughter Flora was born around 1864.
He enlisted in the Union army on September 19, 1861, and mustered in as a private in Company E of the 48th Ohio Infantry on December 7. According to his service records, he was 5 feet, 8 inches tall, with black hair and hazel eyes. The regiment fought in the Battle of Fort Donelson, but it is unclear if Daniels took part. Army officials sent him to the hospital “on account of disability” on April 16, 1862, and he was discharged for disability in Columbus, Ohio, on September 12, 1862.
He re-enlisted on September 16, 1864, and rejoined the 48th Ohio Infantry. Army officials transferred him to the 83rd Ohio Infantry on January 17, 1865, and he probably mustered out that spring or summer. Daniels lived in Dayton, Ohio, and worked as a teamster after the war. He died in Dayton on January 24, 1903.