Cyrus E. Ferguson was born around 1830 in Ohio to James and Margaret Ferguson. His father was a farmer who owned $700 of real estate by 1850. The family eventually moved to Linn County, Iowa, and by 1850, Ferguson was working as a farmer there. He married Martha A. Bryant on April 2, 1857, and they had at least three children: William, born around 1857; Fanny, born around 1860; Grace, born around 1864.
He enlisted in the Union army on December 26, 1863, and he mustered in as a private in Company A of the 15th Iowa Infantry on January 15, 1864. The regiment took part in the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He mustered out on July 24, 1865.
Ferguson settled in Cedar Rapids, Iowa, after the war, and he earned a living as a painter. By 1870, he owned $1,500 of real estate and $1,000 of personal property. He applied for a federal pension in November 1884 and eventually secured one. He moved to Chicago, Illinois, in the late 1800s, and by 1900, he was living in his daughter Fanny’s household there. A decade later, he was living in his daughter Grace’s household in Chicago. He died in Chicago on July 21, 1918.