Sylvester Thompson was born on October 21, 1814, in Bennington, Bennington County, Vermont, the son of Wealthy (b. 1778 in Connecticut).
Sylvester (or Sylvanus) left Vermont and by 1840 had settled in Ionia, Ionia County, Michigan.
He married New York native Cynthia M. Whipple Hardenburg (1826-1907) on September 15, 1854, in Ionia County, and they probably had at least two children: Eva (b. 1856) and Carrie (b. 1866). It is also possible that Sylvester had been married before and had a child from a previous marriage: a son Eugene (b. 1845 in Michigan). And in fact, Cynthia had been married to one Aaron Hardenburg and they had at least three children: a daughter Eleanor (b. 1845 in Ionia), Louisa (b. 1847 in Michigan) and Henry (b. 1850 in Michigan). By 1860 Sylvester and his family were living on a farm in Easton, Ionia County.
Sylvester stood 5’8” with blue eyes, dark hair and a light complexion and was a 48-year-old farmer possibly living in Easton, Ionia County when he enlisted in Company D on March 4, 1862, at Saranac, Ionia County for 3 years, and was mustered the same day. He was possibly related to Thomas Thompson, who would also enlist in Company D and who was probably also from Ionia County. (Company D was composed in large part of men who came from western Ionia County and Eaton County.) Sylvester was reported employed as a Quartermaster’s (“officer’s”) waiter in July, and absent sick in the hospital from August until he was discharged on December 20, 1862, at York, Pennsylvania, for “chronic sinovitis of knee joint and old age.”
After his discharge from the army Sylvester eventually returned to Ionia County, probably to his home in Easton. By 1870 he was working as a farmer (he owned $5000 worth of real estate) and living with his wife and two daughters in Easton. By 1880 he was farming and living with his wife and daughter Carrie in Easton. He eventually settled in Otisco where he was living in 1890.
He applied for a pension (no. 786216), but the certificate was never granted.
Sylvester died in Otisco on December 7, 1893, and was buried in River Ridge cemetery in Belding, Ionia County: section 1, lot no. 8.
In 1895 his widow applied for and received a pension (no. 475310).