William Renwick was born on October 6, 1838, in New York, the son of Thomas (b. 1798) and Janet Turnbull (b. 1798).
Thomas and Janet were married on May 24, 1818, in Southdean, Roxburgh, Scotland. emigrated from Scotland, eventually settling in New York before moving west. Indeed, William probably came to the United States with his parents in 1852, eventually settling in Geneva, Ontario County, New York. The family eventually moved westward, and settled first in Bedford, Calhoun County, Michigan but in 1858 moved to Keene, Ionia County. By 1860 William was a farmer working for and living with his family in Keene (his father owned $2500 worth of real estate).
William stood 5’8” with blue eyes, sandy hair and a sandy complexion and was 25 years old and probably still living in Ionia County when he enlisted in Company D, probably with his cousin (?) James, on February 14, 1862, at Saranac, Ionia County for 3 years, and was mustered the same day -- Company D was composed in large part of men who came from western Ionia County and Eaton County. (He and James were related to John Foulks, whose mother was Jane Renwick; Foulks also enlisted in Company D and was also from Keene.)
In April of 1862 William was reported as a “waiter” for Captain Moses Houghton of Company D, and in May he was awarded the Kearny Cross for his participation in the battle of Chancellorsville on May 3, 1863.
On May 12, 1864, at Spotsylvania, Virginia, Benjamin Morse of Company C and William Renwick captured a stand of colors from the Fourth Georgia Artillery, which eventually earned Morse the Congressional Medal of Honor. The details of the capture, as described by Minnie D. Millbrook in her work on Michigan Medal of Honor Winners in the Civil War, are “while in the line of duty and while on a charge on the rebel breastworks on the morning (3:30 a.m.) of May 12, 1864, at Spotsylvania, Virginia,” Morse “captured a rebel flag (artillery) and that said flag was turned over to the commanding officer of the Regiment and went to Washington, DC. A letter dated September 20, 1864, was discovered in the War Department naming Benjamin Morse as the captor of the flag, and he was also mentioned in a report of General Winfield S. Hancock as the captor. William Renwick of company D, same Regiment, was also named as captor of the flag in the same action, but he too was seemingly overlooked at the time, and as he never applied for a medal he did not receive one.” The medal was issued to Morse on February 24, 1891.
William was transferred to Company A, 5th Michigan Infantry upon consolidation of the 3rd and 5th Michigan Regiments on June 10, 1864, and discharged on May 14, 1865, at the expiration of his term of service.
After he left the army William eventually returned to Michigan. By 1870 he was working as a farm laborer and living with his parents in Keene, Ionia County. He was living in Saranac in 1879, and working as a grocer in 1880 and living as a single man with the Edward Foulks family in Saranac. He was still in Saranac in 1885 and 1888, in Boston, Ionia County in 1890, and in Saranac in 1894 and 1909 and on R.R. no. 12 in 1911 (his younger cousin James also lived on R.R. no. 12).
He was a member of the Old 3rd Michigan Infantry Association. In 1902 he applied for and received a pension (no. 994178).
William may have been married to a woman named Jane.
William died of heart disease on February 18, 1913, in Keene, Ionia County, and was buried in Pinckney Cemetery, Keene Township: row 3, grave 203.