James M. Cline was born around 1833 in South Carolina to Eliza Cline. He graduated from Oglethorpe University in 1855, receiving first honors in Latin and Greek and a gold medal in astronomy. He married a woman named Mary, and they had at least four children: Anna, born on January 12, 1861; Julia, born around 1867; John, born around 1868; and Martha, born around 1873. He worked as a Methodist minister, and by 1860, he owned $425 of personal property. He moved to Albemarle, North Carolina, in the early 1860s.
In June 1862, he received a commission as a chaplain in the 52nd North Carolina Infantry. The regiment took part in the Battle of Gettysburg. He resigned on August 28, 1863.
He returned to South Carolina after leaving the army, and he resumed his work as a minister. By 1880, he was living in Owen, Arkansas. In 1912, a reporter described him as the “oldest preacher in Little Rock conference…His health is perfect. His hearing is fine. His eyesight is all right. He can outwalk any preacher in his conference.” He was also “an astronomer of the first order” who travelled and lectured on astronomy. He died sometime after 1912.