As a boy in the 1950s, Mike Berkus would often stand waiting outside the tunnel of the old St. Paul Saints stadium in Lexington Park, hoping to get autographs as the players walked out. His friend Howard Bream, of Minnetonka, thinks that’s where Berkus’ love for collecting began.

Berkus developed a passion for anything from the Saints or the Minneapolis Millers, Bream said, especially in 1951 when Willie Mays had a brief stint with the Millers before going on to a Hall of Fame career.

As Berkus grew older, his friends said that passion for collecting helped build the sports memorabilia industry. Berkus, 69, of Villa Park, Calif., died of brain cancer on Nov. 20.

After attending the University of Minnesota, Berkus moved to California. In the 1970s, he was one of the first to hold a collectors’ card show, said longtime friend John Broggi, of New Jersey. In 1980, Berkus and a group of collectors held what they called the first National Sports Collectors Convention in a small Los Angeles hotel ballroom. The popularity of what became known as “the National” skyrocketed. Eleven years later, 100,000 people attended the National in Anaheim, Calif., at the apex of the collector craze.

Berkus wasn’t ready for the crowds. Broggi remembers that the aisles were so packed that people couldn’t move and the fire marshal wouldn’t let anyone into the convention center until other people left. Vendors were furious at Berkus, Broggi said. During a vendors meeting with Berkus, “we were about ready to hang him.”

But Berkus displayed what Broggi came to know as his ability to captivate a crowd.

“Mike gets up on the stage and starts his pitch,” Broggi said. “He said, ‘You think you had a bad day. Let me tell you about my day: I met with the fire marshal 17 times. Each time it went badly.’ He went on and on about how he had a tougher day, and at the end, people felt sorry for him.”

Berkus left the National to join a company called Scoreboard, where he became one of the first to sell sports memorabilia on channels like QVC. In 1996, Broggi and Berkus became partners, and both started to run the National. Broggi said it remains the most popular sports memorabilia show in the country, drawing annual crowds of 30,000 to 40,000. When the National first began, according to a blog post on Dave & Adam’s Cardworld website, it cost $50 for a vendor table. It now costs $1,295.

More than having the collectibles, Broggi said, Berkus was driven by the chase of finding the memorabilia, and then making the deal to get it. That translated not only to memorabilia, but to sponsors and advertisers.

“He was a great storyteller,” Broggi said. “No matter how many times I’d hear him tell a particular story, I’d want to hear it again.”

Throughout his life, Berkus’ love for collecting never died, and grew to include records, coins, comic books and nearly anything else of value, Broggi said. Until he got sick, his friend Bream said, Berkus was collecting records and selling them on eBay.

“When you’re a collector, you’re a collector,” Bream said. “It was in the blood.”

Berkus is survived by his wife, Sher, a daughter and five sons, including Nate Berkus, a nationally known interior designer who has his own bedding and dinnerware line at Target.

In an Instagram post, Nate Berkus said of his father, “He was the most generous and funny man and my stepmother and brothers are devastated.” Services have been held.