PITTSBURGH -- People would come up to him at the grocery store or at restaurants or on campus or in class. "We're praying for you!" they would say. They reached him on social media with the hashtag #ConnerStrong. Or through the mail. Pitt fans, football players from across the country, admirers, coaches, everyday folks who never watch football, cancer survivors -- thousands reached out to a running back from Erie, Pennsylvania, to tell him to fight. To let him know they believed he would win. That people he never even thought about are praying for him. That he inspired them. That he would absolutely live to play football again.

They entrusted him with their stories, telling him about their children who survived cancer or about their own cancer triumphs. They entrusted him with the most personal details of their lives, hoping the words they put to paper would be enough to lift his spirits, to give him hope and light and love.

James Conner quickly learned cancer, and all its ugliness, has this way of drawing people in, more than any touchdown run or fingertip catch or last-second score.

When he announced he had Hodgkin lymphoma in December, Conner looked into a camera and said plainly, "Fear is a choice. I choose not to fear cancer." The letters soon started to arrive in bunches. Conner would have a new batch waiting in his locker every day for months. Others came to his apartment or his home in Erie. In low moments, he would head for the boxes and read a few just because.

"To see everybody reaching out, it puts you in better spirits," Conner said now. "It lets you know people care."

Conner completed 12 rounds of chemotherapy over six months, while keeping a rigorous workout schedule -- all with one goal in mind: playing again when the season began. Now cancer-free and completely healthy, he made his triumphant return to the football field on Saturday against Villanova, scoring two touchdowns in a 28-7 win.

He carried the words in those letters with him, with every step, every run, every smile.

"At one point, I had my conversation with God that 'I was ready if you say it's time.'" Millcreek Township School District Superintendent Bill Hall

Conner first met Millcreek Township School District superintendent Bill Hall as a running back and defensive end at McDowell High in Erie. Since then, Hall and others in town have followed Conner's career closely -- especially after the hometown star won ACC Player of the Year honors in 2014.

When Conner was diagnosed with cancer, Hall described the moment in Erie as "very deflating. It was like we all got punched in the stomach." Though the two knew each other only casually, Hall felt he had to do something to help.

So he decided to share personal details about his own cancer fight, how he was diagnosed with acute promyelocytic leukemia and had three life-threatening complications during his treatments.

"During my darkest times in the hospital -- and they were pretty dark -- I always prayed and thanked God for giving me the cancer, and not having it happen to one of my loved ones," Hall wrote in his letter to Conner. "It's God's test for us, and He knows we can handle it. You have a unique and awesome opportunity that only comes around once in a long while. And, it only comes to a very select group of people."

Conner read the words and could not believe somebody he knew had fought through so much adversity. Those words took on greater meaning, especially when Conner began to see what an impact he was making on others going through a similar situation.

He and Hall met with each other over the summer. Hall gave him a big hug then took him through a tour of the school's renovated athletic facilities. On the way, they talked about their experiences fighting cancer

"I tell people a lot of times, my cancer was one of the best things that ever happened to me," Hall said. "You come out of it on the other side with a whole different perspective on everything. It's therapeutic for me to share my story. It was an easy thing for me to sit down and pound something out for him, to let him know from a local basis he's got the support and love, and he's going to be fine."

Andrea Adelson/ESPN.com

Teresa Winslow looked out at her eighth-grade homeroom class at Wissahickon Middle School in Philadelphia and explained what had happened to Conner. Her son, Ryan, is a punter on the Pitt football team and like everybody around Conner, was devastated. "What can we do?" she asked her class.

They suggested they find a big piece of paper and write encouraging messages to him each month. When Winslow delivered the first positive news Conner got from the doctor, she said her students jumped out of their seats, screaming, "This is awesome!" The school television station even kept students updated during morning announcements.

"Needless to say, I'm a real believer in really positive thoughts and vibes and giving positive energy toward others," Winslow said.

What surprised her the most was the impact the decision to stay in touch with Conner had on the students. She shared Conner's story with all 120 of her students., many of whom would stop by her classroom randomly to simply ask how James was doing.

"It tapped into a lot of kids struggling," Winslow said. "James has been an inspiration to a lot of the kids in my school, just the strength alone to see him, this massive kid, run like he did and be so powerful on the field and have to go through this. I think it really grew a lot of empathy. I know it did in my homeroom. They listened intently whenever we spoke about James. A lot of kids in this world don't grow up with a sense of empathy and compassion, so I think it drew out a lot of really good qualities in my students.

"I really don't know the hearts and minds that it touched totally but I'm sure it was a ripple effect. When you throw a pebble in the water and something happens it ripples out. I think James will probably never know how many people he inspired."

Andrea Adelson/ESPN.com

Danielle O'Banion was in the middle of coaching the Kent State women's basketball team when Conner was diagnosed with cancer. O'Banion coached during the 2014-15 season while undergoing her own chemotherapy treatments, deciding to keep living her life without major interruption -- the way Conner did. She did not miss one game.

When she heard the news about Conner's cancer, O'Banion flashed back to her own diagnosis. The morning after her diagnosis was announced, O'Banion walked into her CrossFit gym and had a care package waiting for her. Another gym member, whom she had met once, had left it -- along with a letter detailing her own fight with breast cancer. The package had all kinds of assorted items the woman thought would help O'Banion during her treatments.

O'Banion had never met Conner, but she felt compelled to write and pay it forward, for all the people who gave her love, support, letters and hope.

"One of the things that is helpful to people when you first find out is hearing about how people are on the other side of it, and how people are continuing to live their lives even during the treatment," O'Banion said. "When you're facing that type of situation, you have two choices: You can sit in your room in the dark and cry, or you can roll up your sleeves and get after it. Holding onto the routine was so important to me, because you didn't want people to look at you as if you were a walking dead person. James has set the most amazing example of that."

O'Banion is now an assistant coach at Memphis but has followed every step of Conner's journey. She has a new favorite football player for life.

Andrea Adelson/ESPN.com

Conner got one scholarship offer to a Power 5 school, and that was from then-Pitt head coach Paul Chryst. His staff had a connection to McDowell High, and coach Mark Soboleski talked them into watching tape of Conner. Once they did, they knew they had to have him in their 2013 signing class.

When Conner arrived, he bonded with other freshmen student-athletes who were new to Pitt. One of them was JoJo Chryst, his head coach's daughter and a defender on the Pitt soccer team. Every time he saw her, he gave her a bear hug. And his laugh? "You could hear it throughout the dorm," JoJo said. Conner rushed for 1,765 yards and 26 touchdowns in 2014 under Chryst. But after the regular season ended, Chryst announced he would leave for Wisconsin. JoJo decided to stay in school at Pitt, but would no longer play soccer.

Though she and Conner lost touch, the news of his diagnosis hit her and the Chryst family hard. She decided to sit down and send him a card, hoping he would read the words and know how much he meant to her family.

"James was part of my dad's first recruiting class that was completely his own. These were his first kids, and I know he felt bad leaving them," JoJo said. "I just hated to see James struggling because he was always so happy. I wanted to reach out to him. I knew I could take 10 minutes out of my day to write him a letter. I was at the point where it was like anything I can do to give a little hope."

"My daughter was diagnosed with Hodgkin Lymphoma just like you. Our world, as did hers, kind of fell apart upon receiving the news. She, like you, though, had a great and positive attitude. She never felt sorry for herself. ... James, always stay positive. There are so many people pulling for you, tons of prayers and well wishes." JoAnne Gates

Five years ago, JoAnne and Tom Gates learned their youngest daughter, Andrea, had cancer. Andrea never pitied herself, but it was easy to get down sometimes. One of the biggest boosts she got was reading all the cards and letters that came to her. Every day, Andrea would run out to the mailbox like it was her birthday to see whether she got a new batch.

So when Conner announced his diagnosis, it hit a soft spot with JoAnne. She and her husband graduated from Pitt. So did Andrea. They live in Pittsburgh and "bleed blue and gold." Though nobody in the Gates family had ever met Conner, JoAnne knew what she had to do to help.

She had to write. Then she got on the Pitt message boards and encouraged fans to send him cards and letters. Not just once -- as many times as they could.

"Those cards were so important," JoAnne said. "When you're not in that situation, you don't think about it, and when you see what it does for someone, it gives them hope at a time when they just don't know whether they're going to live or die.

"Cancer can be very lonely. It's kind of like you are alone on a lifeboat, not knowing if you will be rescued. While you are on this lifeboat you are forced to watch the rest of the world proceeding as usual. You watch your friends get married, have children, play football and you are helpless to do anything but wait and pray. The cards and letters are sort of a lifeline encouraging you that you will be rescued and able to enjoy a normal, beautiful life one day."

Andrea is cancer free.

When Conner takes the field Saturday against Penn State, he will hear from 60,000 fans still marveling at his comeback -- and pinning their hopes for a win over a bitter rival right on him.

These letters are still with him, some in boxes in his apartment, others in boxes in Erie. He saved every envelope because one day, he plans on sitting down and writing to every single person who wrote him and encouraged him and prayed for him.

He hopes all those friends and strangers get as much out of his letter as he got out of theirs.