John S Lee was born 22 March 1826 in New London County, CT. He came to Livingston County, IL about 1859 and is in Pontiac for the 1860 census.

Record Source: Illinois Civil War Muster and Descriptive Rolls

Name: John S Lee Rank: Private Company G 129th Illinois Infantry

Height: 6' 3 Hair: DARK Eyes: BLUE Complexion: LIGHT

Marital status: Married Occupation: Blacksmith

Birth Date: Abt 1826 Birth Place: Colchester, New London CO, CT

Service Entry Age: 36 Date: 2 Aug 1862 Place: Pontiac, IL

Muster In Date: 8 Sep 1862 Muster In Place: Pontiac, IL

Muster Out Date: 8 Jun 1865 Muster Out Place: Washington, DC

Residence Place: Pontiac, Livingston CO, IL

After the war they are still living in Pontiac, listed in both the 1870 census and the 1880 census. Eunice died 2 Dec 1895 in Pontiac, IL. In both the 1900 and 1910 census, John is living with his daughter Addie and family in Pontiac. John S Lee died 13 Apr 1913 in Pontiac, Livingston County, IL.

The Find A Grave website for Southside cemetery has this obituary from the Pantagraph.

J. S. Lee Answers Final Summons. Pontiac, April 14. - John S. Lee, one of the old residents of Pontiac, and a highly esteemed citizen, who had been paralytic for a number of years, passed away at the home of his daughter, Mrs. Joel Allen, 307 East North street, about 9 o'clock Sunday evening.

John S. Lee was born in New London, Conn., March 22, 1826. He grew to manhood in that place and learned the trade of blacksmith. He worked at that trade until he moved to Illinois with his family in 1858. He came first to McLean county and then to Pleasant Ridge Township, this county, and there engaged in farming for two years. He came to Pontiac in 1860, and again engaged in his trade of blacksmithing. In 1862, he enlisted in the 129th Illinois Volunteer Infantry and remained until the close of the war.

Mr. Lee was married to Miss Eunice Packer of Colchester, Conn., on November 26, 1848. To this union were born four children, Addie E., now Mrs. Joel Allen of this city, Hattie L., now Mrs. J. R. Roggy, of Trumbul, Neb., Frank P., of Omaha, Neb., and Charles H., of Pullman, Ill.