Clark Smiley Gordon was born around 1828 in Moultonborough, New Hampshire, to Clark and Susannah Gordon. His father was a farmer who owned $2,000 of real estate by 1850. The family lived in Alexandria, New Hampshire, and by 1850, he was also working as a farmer. That year, he owned $1,000 of real estate.
He enlisted in the Union army on April 25, 1861, and he probably served in a three-month regiment. He rejoined the Union army on August 22, 1861, mustering in as a private in the 1st New Hampshire Light Artillery. According to his service records, he was 5 feet, 6 inches tall, with brown hair and blue eyes. The regiment took part in the Second Battle of Manassas, the Battle of Antietam, the Battle of Fredericksburg, the Battle of Chancellorsville, the Battle of Gettysburg, the Overland Campaign, and the Appomattox campaign. As the presidential election of 1864 approached, he confessed that he was a “strong McClelland man still I dont think I could vote against Old Abe.” He mustered out on June 9, 1865.
He settled in Lyndeborough, New Hampshire, after the war and worked in a grist mill. He applied for a federal pension in March 1886 and eventually received one. He died of “paralysis of [the] heart” in Lyndeborough on October 3, 1886.