Born in Wichita Falls, Texas, Jacob was the son of Hiram Herbert Fisher, an oil field worker, and Mary Elizabeth Schulte Fisher. The family moved to Louisiana, where Jacob finished high school in Homer. He yearned to enter the service, but suffered from asthma. He kept his condition a secret, and hid his adrenalin vaporizer. "I should have been 4-F," he says. Jacob joined the U.S. Navy, took boot camp at Farragut, Idaho. So desperate was the Navy for corpsmen in the Pacific, Jacob was sent straight from boot camp into Hospital Corps School, also in Farragut. He shipped out to the Pacific and was assigned to the USS Dorian, which was turned into a hospital ship for the Tarawa campaign. Jacob worked in the laboratory and assisted in operating rooms. Of his experience he says, "I can't get over how young we were and how we were able to cope with some of that, when I look back now to these youngsters that are seventeen and eighteen, as an old man almost eighty now." From aboard the USS Calvert he went ashore in the third wave in the invasion of Kwajalein. He also participated in the invasions of Saipan and Tinian. While not in combat, Jacob remained aboard ships where he prepared bandages and trained by taking "casualties" from the engine room to sickbay. Much of his medicine was sulfa powder to sprinkle on wounds, and morphine in tablet form. Jacob was hospitalized in Pearl Harbor with bronchitis but recovered. He was transferred to Kauai Amphibious Training base from September to December of 1944, then was sent to the Philippines. Jacob returned to the states in April of 1945, just as he turned twenty. While attended Louisiana Tech he met Nell Davidson, and married her on August 13, 1949. They would have two children and three grandchildren. Jacob graduated from Centenary College and then Southwestern Baptist Theological Seminary in Fort Worth. Believing "the Lord called me into the ministry as a chaplain," he re-entered the Navy as a chaplain and served aboard transport ships, cruisers, a guided missile experimental ship, and the famous aircraft carrier, USS Lexington, among others. He retired July 1, 1972. Jacob worked as chaplain at LSU Medical Center in Shreveport until 1995.