James T. Thompson was born on February 3, 1843, in present-day Metcalfe County, Kentucky, to George and Mary Ann Thompson. His father was a farmer who owned $3,500 of real estate and $6,000 of personal property. He grew up and attended school in Metcalfe County. By the early 1860s, he was working as a farmer.
He enlisted in the Union army on October 2, 1861, and he mustered in as a sergeant in Company K of the 21st Kentucky Infantry on December 30. According to his service records, he was 5 feet, 11 inches tall, with dark hair and blue eyes. The regiment took part in the Battle of Perryville, the Battle of Stones River, the Battle of Missionary Ridge, and the Atlanta campaign.
He opposed emancipation, but he remained fiercely devoted to the Union. As he explained in September 1863, “I believe that it is Right that negrows should serve the whites and be ther slaves the union as it was and the constitution as it is is what we are after.” Later that month, he added, “I never believe the government of Washenton will go to distrucktion while one Rag of the old flag remans untrampled down and the memory of washenton Jackson and other grate men are in ther bosoms.” He opposed the “Ablishenist party,” and he insisted that the “conservative men…are the men that will have to restore the union.” He mustered out on January 20, 1865.
He settled in Lafayette, Kentucky, after the war, and he married Mary C. Yates. They had at least four children: George, born around 1867; Mary, born around 1869; Thomas, born around 1873; and Beulah, born around 1878. He worked as a farmer, and by 1870, he owned $1,000 of real estate and $1,300 of personal property. He applied for a federal pension in March 1879 and eventually secured one. His wife died in the late 1800s. He married Elenora Cox, and their daughter Dixie was born around 1913. He died of bronchial pneumonia on October 25, 1927, in Sulphur Well, Kentucky.