Al Geiberger won the "Danny Thomas Memphis Classic" on May 20, 1977. He won by three shots over Gary Player and Jerry McGee.

The site was special for Geiberger not only because of the victory, but because it was also where he shot the now famous famous 59 (during the second round).

During his career, Geiberger won 30 professional events, 11 of which were on the PGA Tour. Among those victories was the 1966 PGA Championship. He also holds top 15 finishes in the other three major events. 

Geiberger had much success on the Champions Tour, winning 10 times, and will forever hold a spot in golf history

https://en.wikipedia.org/wiki/Al_Geiberger

Jerome Travers was born May 19, 1887. Travers won the US Amateur 4 times between 1907 and 1913. He is also known for being one of the five amateurs to have won the US Open (which he did in 1915). 

During his amateur career, Travers also won five Metropolitan Opens and Three New Jersey Amateur Titles. 

According to his hall of fame profile, he was taught by Alex Smith, winner of two US Open titles (1906 and 1910).

Later in life, Travers published a golf book entitled "Travers Golf Book," which outlined strategies for improving one's game, the history of Traver's golf career, and many other secrets of his incredible talent. 

http://en.wikipedia.org/wiki/Jerome_Travers 

http://www.worldgolfhalloffame.org/hof/member.php?member=1114

On May 18, 2008, Ryuji Imada won the AT&T Classic in a sudden death playoff over Kenny Perry. It was a redemption of sorts for Imada, as he had lost to Zach Johnson the year before at the same tournament, also in a sudden death playoff. 

Although that remains Ryuji's only PGA Tour win, he has two wins on the Nationwide Tour, top 20's in the US Open and Masters, and over $9,000,000 in career earnings.

https://en.wikipedia.org/wiki/Ryuji_Imada

Hunter Mahan was born May 17, 1982 in Orange, Ca. He is currently a member of the PGA Tour, and has 5 PGA Tour wins to his credit.

During his amateur career, Mahan won the Junior Amateur and was runner up to Ricky Barnes at the US Amateur in 2002. He play has been steady ever since turning pro in 2003. He notched one win in 2007, and then two more in 2010. With his win at the Houston Open in 2012, he became the highest ranked American in the world, at number 4 in the official rankings. 

https://en.wikipedia.org/wiki/Hunter_Mahan