I saw Steve Earle on a Sunday night at the Neptune in Seattle last September; he played for 2 1/2 hours and stuck around afterward to sign records.

My then fiancee (now wife) and I got a photo with him. And I remember thinking at the time how strange it was that an artist of Earle’s stature and longevity would be signing things and snapping photos with fans. I mean, this guy wrote “Copperhead Road,” you know. This guy, who is at the Capitol Theatre on June 19, renewed country music’s outlaw spirit and served as an inspiration for the current Americana movement.

And here he was signing autographs, indulging every fan willing to shell out $20 for a record.

Then again, that’s what it takes to make money in today’s music industry. Unless you’re U2 or Katy Perry, you’ve got to tour relentlessly. You’ve got to move merchandise at your shows, and a lot more people are going to buy a record if they can get it signed right there on the spot.

So there was Earle — one of the most important and acclaimed singer-songwriters of the past 30 years — graciously accepting the reality of that situation. The man has bills to pay. His youngest son, John Henry, is autistic and attends an expensive school. And Earle, who wasn’t then but is now in the midst of his seventh divorce, has never exploited his talents to their full commercial potential. Instead, he has pursued an iconoclastic career path that has included burning down the country music establishment that could have been a bank for him.

He acknowledges that his artistic direction, not so much anti-commercial as unconcerned-with-the-commercial, has narrowed his appeal. His 1986 debut, the straightforward country album “Guitar Town,” remains his only No. 1 album. By the time his third album, 1988’s “Copperhead Road,” was released, Earle had become unclassifiable. He was somewhere between rock and country, charting a new course artistically but not quite appealing to either side’s mainstream core.

Then there was heroin, cocaine and prison. Then recovery, sobriety and an increasingly strident brand of political activism, which peaked (as far as public awareness and controversy are concerned) with his 2002 song “John Walker’s Blues,” written from the point of view of American Taliban fighter John Walker Lindh.

He also released songs explicitly critical of George W. Bush during a time when such opinions could seriously imperil a country musician’s career — see Chicks, Dixie — and more recently aligned himself with the “99 percent” of the Occupy Wall Street movement. He knows he loses part of his audience every time he makes a move like that.

“But I’m pretty proud of my audience,” Earle said in a phone interview earlier this month. “It’s smart. ... I lose people when I do the political stuff, and I don’t apologize for that at all.”

And why should he? His has been a singular career. He dropped out of high school to pursue music, hooking up with Guy Clark’s band when he was still a teenager and learning at the feet of his songwriting hero, the legendary Townes Van Zandt.

“It was an old-fashioned kind of apprenticeship,” Earle said of Van Zandt. “And I think he realized that and took it very seriously.”

The two shared a complex relationship that is at the heart of Earle’s upcoming memoir. They were similarly stubborn about making the music they wanted, and they had similar demons. By the time they met, Van Zandt was basically already dying slowly from substance abuse, to which he finally succumbed on New Year’s Day 1997. Earle doesn’t say it in these words, but Van Zandt must have been a cautionary tale of sorts.

“I did distance myself from him years and years ago,” Earle said. “I could see him, but I couldn’t hang out with him.”

That said, when Earle was at his lowest, Van Zandt did try to reach him.

“You know you’re in trouble when Townes Van Zandt shows up at your house to give you a temperance lecture,” he said.

The drugs and the recovery have since been a recurring theme in Earle’s music, not always explicitly but in the redemptive spirit of the songs. Much of his best work has come during the past two decades of sobriety, including the classic 2000 album “Transcendental Blues,” from which came crowd favorites such as “The Galway Girl” and “The Boy Who Never Cried.”

Aside from the music, Earle has become a 21st century Renaissance man, writing plays and a novel as well as appearing as an actor in “The Wire” and “Treme” and several indie films. The acting, in particular, is something he never imagined doing.

“I was offered film roles when I was a lot better looking,” he said. “And I turned them down. I always hated it when actors made records.”

All of the other projects are unlikely to supersede his day job, he said. But they may overlap.

“I’m actually thinking about writing a musical,” Earle said. “So there will be music in it, and I’ll probably put out records of those songs. And they probably won’t suck.”

That’s one of the reasons he moved to New York from Texas a few years back. The theater may allow him to create without having to tour.

“I’m going to be 60 years old my next birthday,” he said. “So I have to think about that stuff. But I’ll never retire.”

For now, he’s still on the road, playing shows for the cult of fans that’s stuck with him — and catching the occasional baseball game on an off day. Part of him wants to do that till he keels over (“I like to think I’m going to spontaneously combust in the back of the bus,” he said) and part of him wouldn’t mind being around a little more as John Henry grows up.

From an audience perspective, his shows remain compelling. He still plays the old stuff, as well as the new. He still has control of his career. And, yeah, maybe that means he was never as big a star as he could’ve been. Maybe it means he still has to care about whether you buy an album at the show.

But when you see him afterward, signing autographs and posing for fans, you’ll see Steve Earle doing what he has to do, his own man as always.