James R. McGibbon was born around 1839 in Sorel, Canada. He eventually immigrated to America and settled in Vermont. By the early 1860s, he was working as a farmer.
He enlisted in the Union army on August 23, 1861, and he mustered in as a private in Company H of the 5th Vermont Infantry on September 16. According to his service records, he was 5 feet, 7 ¼ inches tall, with black hair and black eyes. The regiment took part in the Battle of Antietam, the Battle of Fredericksburg, the Battle of Chancellorsville, the Battle of Gettysburg, the Overland Campaign, and the siege of Petersburg. He mustered out on June 29, 1865.
He settled in Goshen, Vermont, after the war, and he married a woman named Ellen. He earned a living as a farmer. He applied for a federal pension in August 1869 and eventually secured one. He died around 1898.