Palmer pulls a driving iron from his golf bag on a golf course in 1953.
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Palmer and his wife Winnie during the Masters Tournament at Augusta National Golf Club in Augusta, Georgia in April 1958.
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President Dwight Eisenhower, right, enjoys a laugh with Palmer, just before they played a round of golf together in a foursome at the Gettysburg Country Club in Gettysburg, Pennsylvania on Sept. 9, 1960.
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Arnold Palmer holds the trophy cup after he defeated Johnny Pott, 69-73, in a 180-hole playoff match at the Colonial National Invitation golf tournament at Fort Worth, Texas on May 14, 1962.
At a time when some professional golfers were still tooling around the course in plus-fours, Palmer popularized a modern, exciting form of golf on the edge, often scrambling to save par or even come in under par after having driven off-line into the woods or a bunker.
Palmer slips into his green jacket with help from Jack Nicklaus after winning the Masters golf championship, in Augusta, Georgia on April 12, 1964. Palmer pursued a rivalry with Jack Nicklaus -- whose own nickname, "the Golden Bear," illustrated the differences in their styles and personalities -- that thrilled fans for three decades.
Nicklaus and Palmer at the National Four Ball Championships in Ligonier, Pennsylvania on July 25, 1970.
In a note posted to Twitter on the day he died, Nicklaus called Palmer one of his best friends, saying they last spoke on Palmer's birthday, Sept. 10. Palmer sounded great, Nicklaus said. "I know he was in Pittsburgh trying to find out how to make himself better," Nicklaus wrote. "That's what Arnold has always tried to do. He has always been a fighter and he never gave up on anything."
Nicklaus added, "Arnold transcended the game of golf. He was more than a golfer or even great golfer. He was an icon. He was a legend. Arnold was someone who was a pioneer in his sport. He took the game from one level to a higher level, virtually by himself."
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Palmer takes a putt in a match against Bob Charles during the Piccadilly World Match Play Championship at Wentworth on 7th October 1971.
He played by the seat of the pants that he regularly hoisted back up to his waist -- an everyman gesture that endeared him to duffers around the world. They were known as "Arnie's Army."
Palmer and entertainer Bob Hope examine a bent golf club during the filming of 'Call Me Bwana' at Denham in west London.
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Palmer looks at a statue of himself commemorating the 50th anniversary of his first PGA tour win in 1955 at the Weston Golf and Country Club in Toronto Sept. 13, 2005.
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Palmer hits from a sand trap during the annual Masters Par 3 golf tournament at the Augusta National Golf Club on April 9, 2008.
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Palmer bows and tips his cap after hitting his tee-shot on the first hole during a pro-am event at the Arnold Palmer Invitational golf tournament in Orlando on March 12, 2008.
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Golf great Arnold Palmer reacts to the fans during the Par 3 contest before the 2010 Masters golf tournament at the Augusta National Golf Club in Augusta on April 7, 2010.
His biographer, James Dodson, told NBC News on Sunday: "He was the most charismatic player in golf history. Because of him, golf boomed. He took it from being a sleepy country club game to America's game."
Palmer hits a ceremonial first tee shot during the first round of the Masters golf tournament at Augusta National Golf Club on April 7, 2011.
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Golfing great Palmer receives the Congressional Gold Medal from House Speaker John Boehner of Ohio, left, during a ceremony in the Rotunda of the Capitol in Washington on Sept. 12, 2012.
Tiger Woods embraces Palmer after he wins the Arnold Palmer Invitational at Bay Hill Golf and Country Club on March 25, 2013 in Orlando, Florida.
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Palmer of kisses his wife Kathleen as they pose for a photograph on the first green during the Champion Golfers' Challenge tournament ahead of the British Open golf championship on the Old Course in St. Andrews, Scotland, July 15, 2015.
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Palmer after he arrived to begin Round 1 of the 80th Masters Golf Tournament at the Augusta National Golf Club on April 7, 2016.
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Palmer waves on the 18th green during the Champion Golfers' Challenge ahead of the 144th Open Championship at The Old Course on July 15, 2015 in St Andrews, Scotland.