Charles M. Goodwin was born around 1836 in Brewer, Maine, to Benjamin Goodwin and Clarissa Stearns. His father was a lumber merchant who owned $6,400 of real estate in 1860. Goodwin attended school in Brewer before beginning work as an engineer. Goodwin enlisted in the Union navy during the Civil War, becoming an acting third assistant engineer on November 11, 1862. According to his service records, he was 5 feet, 9 inches tall, with brown hair and brown eyes. By May 1863, he was serving aboard the USS Madgie. He was discharged on September 6, 1865. He returned to Maine after the war and married Caroline A. Doe there on May 4, 1868. He died in Brewer on April 12, 1883.