Turning professional after winning the 1954 U.S. amateur championship, won the 1955 Canadian Open. Won the Masters tournament in 1958, 1960, 1962, and 1964, becoming the first four-time winner; the U.S. Open in 1960; and the British Open in 1961 and 1962. A great fan favorite, followed enthusiastically by "Arnie's Army," had a noted long-term rivalry with Jack Nicklaus. In 1967 he became the first golf professional to have won over $1 million. In May 2005, hosted the U.S. Senior Open Golf Championship as his home course, Laurel Valley Golf Club.