Urbane B. Harris was born on February 10, 1833, in Beaver Creek, Illinois, to John and Nancy Harris. He grew up and attended school in Beaver Creek before beginning work as a teacher. He married Elizabeth Ann Gregory on February 1, 1853, and they had at least three children: Margaret, born around 1855; Luther, born around 1857; Milton, born around 1859; and John, born around 1868. They lived in Bond County, and Harris worked as a farmer. By 1860, he owned $1,600 of real estate and $800 of personal property.
In October 1862, he received a commission as captain of Company E of the 130th Illinois Infantry. According to his service records, he was 5 feet, 11 ½ inches tall, with dark hair and blue eyes. The regiment took part in the Vicksburg campaign. According to an early biographer, he was “a faithful soldier, but his arduous service proved too much for his health.” By early 1864, he was suffering from rheumatism and malaria, and he resigned on February 13, 1864.
He returned to Beaver Creek after leaving the army, “for a long time after the expiration of his service he was unable to do any work.” In 1868, he received an appointment as a local postmaster. By 1870, he was working as a farmer, and he owned $13,000 of real estate and $4,250 of personal property. He moved to Greenville, Illinois, around 1883. He applied for a federal pension in August 1890 and eventually secured one. He was reportedly a “stalwart Republican,” and he served on the county Board of Supervisors for ten years. He also served as mayor of Greenville. He died in Greenville on August 7, 1891.