As Harry Glickman tells it, the decision to grant Portland an NBA franchise came down to a forgotten raincoat, a locked bathroom and a harrowing drive through downtown Los Angeles to Beverly Hills.

The Trail Blazers are now entering their 50th season of play. The NBA is arguably at the height of its popularity — a social, cultural and (as we’ve seen recently) political force.

THANKS TO OUR SPONSOR: Become a Sponsor

At one point, it seemed unfathomable a professional basketball franchise would land in Portland. Now, the city plays home to the last NBA team in the Pacific Northwest and it’s become equally unfathomable to imagine a Portland without the Trail Blazers.

Related: The Stanley Coup: How Portland Put Its Name On Hockey's Top Prize

Glickman, a sports promoter — who, among other jobs, backed the Portland Buckaroos hockey team — had originally pitched his home city as a prime location for professional basketball in the mid-1950s.

At the time, though, the National Basketball Association had been allergic to westward expansion. League president Maurice Podoloff, now the namesake of the NBA's most valuable player trophy, instead focused on keeping the league viable through its early years.

Harry Glickman was influential in bringing the NBA to his hometown. In 1970 he helped secure the expansion bid that led to the Portland Trail Blazers. Oregon Jewish Museum and Center for Holocaust Education

"He couldn't understand anything west of Brooklyn," Glickman said in a 2015 interview with OPB's "Oregon Experience."

It got to the point where Glickman was instead vying for an NFL team because basketball, he wrote in his 1978 book "Promoter Ain't A Dirty Word," had lost his interest.

That changed when commissioner J. Walter Kennedy took helm of the league. Kennedy led an aggressive westward expansion, helping bring pro ball to cities such as Chicago, Houston, Seattle and Phoenix.

The NBA had expansion on the brain again in 1970. Abe Pollin, who owned the Washington (nee Baltimore) Bullets, chaired the expansion committee — and he was also a big supporter of a Portland franchise. Portland was among the frontrunners for one of the four expansion spots, but Glickman had to show he was good for the money.

THANKS TO OUR SPONSOR: Become a Sponsor

In the rush to pull together funds on short notice, Glickman forgot his raincoat in Pollin's hotel room. When he went to retrieve it, Pollin had a call waiting for Glickman from Seattle real estate developer Herman Sarkowsky. Sarkowsky, who later helped bring the NFL's Seahawks to Seattle, had recruited fellow developers Robert Schmertz of New Jersey and Larry Weinberg of Los Angeles to put up the rest of the money Portland needed to secure the team.

“I went to retrieve the raincoat — it’s a true story,” Glickman said. “If I hadn’t done that, [the Blazers] might not be here yet.”

But Glickman wasn’t out of the damp, old growth woods just yet. He still needed credit approval for $750,000 in the form of a signed letter, which needed to be on the committee table by noon the following day.

Glickman got caught up the next morning with a chatty banker in downtown LA who was burning precious time with questions about the NBA and excessive concern over a typo.

“I said, ‘Don’t bother with that, just initial it and give me the damn letter,’” Glickman wrote.

When he finally pried the signed letter of credit from the banker’s hands, Glickman still had to drive to the committee hotel “a million miles away” in Beverly Hills. (“There’s no way that’s gonna happen,” he said in the 2015 interview.)

Meanwhile, Pollin, knowing his Portland counterpart was running late, excused himself from the expansion meeting — remember, he was the chair — went to the bathroom and locked himself inside.

“And he said, ‘Don’t anybody call me outta here until Glickman gets here with that piece of paper!’” Glickman recounted.

And that’s about how it went down. Glickman arrived, handed over the letter and a few hours later, Portland had an NBA team. The Trail Blazers won 29 games in their first season, which was, at the time, the second-best record for any NBA expansion team. They won their only NBA title in 1977.

The story of the Trail Blazers’ founding has been told before. Often, in fact.

But the story of the Trail Blazers is more than just a forgotten raincoat, a locked bathroom and a harrowing drive through Los Angeles.

Portland was a changing city in 1970.

"... [I]n terms of culture, in terms of the relationship between men and women, between whites and blacks, between gays and straights, everywhere you looked the old certainties and the old structures were falling apart," wrote Maurice Isserman, who at the time worked for underground newspaper The Willamette Bridge.

Professional basketball’s arrival in Portland is a story of land and community. Money and politics. How sport can shape a city and how a city can shape sport. As the first 50 years of the Trail Blazers end and the next 50 years begin, those stories will come into clearer focus.