Coleman W. Doolittle was born around 1840 in Wolcott, New York, to Loren Doolittle and PhebeWorth. His father was a lawyer who owned $550 of personal property in 1860. He grew up and attended school in Wolcott, New York, and by 1860, he was working as a farmer. He enlisted in the Union army on January 12, 1864, and mustered in as a private in the 16th New York Heavy Artillery on January 26. According to his service records, he was 5 feet, 8 inches tall, with red hair and black eyes.
The regiment took part in the siege of Petersburg, and Doolittle was eventually promoted to corporal and then sergeant. He mustered out in Washington, D.C., on August 21, 1865.
He settled in Dowagiac, Michigan, after the war, and he married Emeline Doolittle there on November 24, 1867. They had at least three children: Cora, born around 1871; Gracie, born around 1879; and John, born around 1881. By 1870, he was working as a mason, and he owned $800 of real estate and $200 of personal property. They moved to Kearney, Michigan, sometime in the 1870s. He died in Michigan on August 9, 1913.