In July 1861, he was commissioned a major in the 20th Massachusetts Infantry. In October 1861, at the Battle of Ball's Bluff in Virginia, Revere was wounded and captured by the Confederate States Army. He was paroled in February 1862 and officially exchanged in May 1862. In September 1862, Revere participated in the Battle of Antietam, in which he suffered a second wound and Edward Hutchinson Revere, another of Paul Revere's grandsons, was killed. On July 2, 1863, Revere, by now colonel of his regiment, was mortally wounded at the Battle of Gettysburg and died two days later.