Leo Carlin was just a North Philadelphia kid fresh out of the Marine Corps, newly married and willing to work, and all of a sudden he was selling tickets for the Philadelphia Eagles in 1960. Five franchise Owners and 14 head coaches later, Carlin is in the Eagles Hall of Fame with a lifetime of memories and a world of friends and admirers.

"It's a ride I wouldn't trade for anything else," Carlin says. "It's magnificent. It has been so much fun. Fifty-five years. I keep saying it to myself because I just can't believe it. Fifty-five years …"

Carlin retires at the end of April, ending an unprecedented run in the Eagles' ticket office. The longtime team ticket manager oversaw the 1960s years at Franklin Field and then transitioned those fans to the state-of-the-art, multi-purposed Veterans Stadium (and back again to Franklin Field for one more year when Veterans Stadium wasn't ready for the start of the 1970 season) and executed the monumental task of housing the fans at Lincoln Financial Field when it opened in 2003.

The chances are great that if you have ever witnessed an Eagles home game since 1960 - he started part time in 1960 and joined the Eagles in a full-time capacity in 1964 - that Leo Carlin helped you in some way. That's just how he did business - with a confident hand, a caring heart and a gentle touch.

"I've been meditating on how much things have changed in my time here. Fifty-five years. That just blows me away," he says. "I was just a kid out of college and fresh out of the Marine Corps and had just gotten married and all of a sudden I'm with the Philadelphia Eagles and we're on our way to winning the NFL Championship. People ask me who my favorite Eagles team has been and it's always the 1960 Eagles. They got me hired.

"I feel like, yes, in many ways I touched every person who had a ticket to an Eagles game in the last 55 years. They all sort of became familiar with me, some of them who go back to the days of Franklin Field, and even if they don't know me personally they tell me how much it meant to their parents that I got them tickets. I may not know who they are, but it is so wonderful that they are happy.

"The very fact that a fan would walk up to me and want to shake hands with me so that they could thank me just blows me away. It always has. I take all of that to heart. I really do. If I had to leave a message to the fans, it would be that I cared, and that I tried for each and every one of them. That's what matters."

Carlin ticks off the numbers and visualizing the seating challenges – 60,658 seats at Franklin Field, 65,358 capacity at the Vet and now 69,176 who cram Lincoln Financial Field every gameday. He worked through the years with great diligence and dignity, understanding the importance of taking each fan's needs into account as he moved through the various configurations of the stadiums. There was the collegiate feel of Franklin Field, where the Eagles won the 1960 NFL Championship. Veterans Stadium ushered in the modern era of dual-purpose stadia and multiple levels in seating and luxury boxes. Lincoln Financial Field was the most difficult task. How could Carlin accommodate so many needs as well as navigate the Stadium Builder Licenses and keep everybody happy?

"It was my greatest challenge because we had the seat licenses," said Carlin, who has seven children and 22 grandchildren. "I wanted people as close to their section that they enjoyed at Veterans Stadium. I was very sympathetic to the requests from the fans and it was very, very complicated. The formula changed almost every day. I'm amazed at what good feedback I received. People say to me, to this day, 'Thank you very much Leo, for what you did.' That is what this job has always been about. My job was to make people happy."

Carlin was rewarded for his great work and his loyalty and his remarkable reach with the fans when he was inducted into the franchise's Hall of Fame in 2012. A pioneer in the business who helped the Eagles lead the way into the modern computer age in ticketing, Carlin remains overwhelmed by the honor.

"Being inducted into the team's Hall of Fame means so much. I have to thank Jeffrey Lurie for that," Carlin said. "I admit that when I walk into the building (Lincoln Financial Field's HeadHouse Plaza) every day I look up and see my name. I shouldn't admit that, but I do. That took place in front of almost my entire family. Do you know how much that means to me? It meant everything and it still does.

"Jeffrey called me into his office and told me that I was going to be inducted into the Eagles Hall of Fame. How do you react to those words? And then he spoke to the press and he started out by saying what I meant to him and to the Eagles for 53 years (in 2012). It was remarkable. I've thanked him so many times. It was just a remarkable experience. I treasure it. And to have my family on the sidelines for that night was everything for me. I cried. I can't tell you how emotional things were for me with that entire experience."

"Fifty-five years and I can't count all the friends I've made. Players, coaches, the people I work with and have worked with here and throughout the league. I'm so proud of that. So happy about every minute I've spent here. The fans. The people who stay in touch to this day. It has been a long laundry list and I can't come close to naming names. The fun I've had here and the experiences through the years are things that I will always cherish. "

Carlin has never watched an entire Eagles home game. He's been too busy doing the accounting, stamping out fires and making sure the fans were happy. Now, he may just sit back and soak in the action and watch with a gaggle of his grandchildren at his side.

"I think it would be very hard for me to do that," he says, laughing, "but I might try. I have some time now." !

• VIEW: Leo Carlin: A Lifetime Of Tickets And Memories