James was born April 7, 1928 in Norman, Oklahoma. After a tough childhood, he joined the Merchant Marines, then the National Guard, then served in the Army, fighting in the Korean War. He was wounded twice and honored with two Purple Hearts. He was actually born with the last name Bumgarner but changed it to Garner once he got into showbiz and the studio decided to credit him with "Garner" as his last name.
James married Lois Clarke in 1956, and it sounds like they had something of a Notebook-worthy love story themselves. They wed two weeks after they met at a political rally. "She just knocked me out," he said (via People). They had one child together, Gigi Garner, and Lois had a daughter Kim from a previous marriage. All three women survive him.
James had chronic knee issues over the years, and also had quintuple bypass heart surgery in 1988. He also had surgery in 2008 after a minor stroke. Last night, TMZ said an ambulance was called to his L.A. home around 8 p.m., but he had already passed when they arrived on scene.
He was a great man who lived a fascinating life, and you can read more about his impressive story here. Our condolences to his family, who must miss him already.
Update (July 29, 2014): Citing James's death certificate, TMZreports that the cause of death has been identified as an acute myocardial infarction, i.e. a heart attack.