On Saturday, March 19 — as the 30th annual South by Southwest Festival wound down to a close — South Congress Avenue swam with locals and tourists.

Though the weather had turned chilly, folks dressed in funky outfits strolled slowly up and down the wide sidewalks. Peaceful and relaxed, they stopped to chat, to drink in some street music, or to browse the hand-made crafts hawked by outdoor vendors. Some ventured into shops or eateries, virtually all of them locally generated.

At scattered spots along the way, eager young activists used their charms to sign up passers-by for idealistic causes. Every once in while, one could catch the foxy whiff of a still-forbidden substance.

If the alert observer squinted very hard — and blocked out decades of intervening memories — one could almost be transported to Austin’s Drag along Guadalupe Street opposite the University of Texas campus in the 1970s.

Sure, the hair is shorter, the crowd is more varied, the causes have evolved, and the prices on those modish crafts have skyrocketed. Yet so much about Austin’s culture in the 2010s reflects an unmistakable provenance in the 1970s.

What was it about that fervent era — when “hippies” took over the Austin City Council, music sprang up on every street corner, nightlife extended well into the morning, the counterculture spawned its own version of a start-up revolution, and people of color finally secured a grasp on the levers of power— that left such a seemingly permanent imprint on this city?

And why did that decade’s counterculture become what is now arguably Austin’s dominant culture, as the New Austin of the 1970s confronts the Newer Austin culture of the 2010s?

Intrigued by the number of local hotspots that celebrated their 40th anniversaries recently, we asked several dozen thoughtful Austinites who remember that time to share their reflections on how that decade affected this one.

Retired advertising executive Forrest Preece — an Austin native whose family goes back generations in Central Texas — shares a telling memory.

“One weekend in 1972, a friend from Houston came up to visit,” Preece recalls. “On Saturday, we ate breakfast at Cisco’s and we were driving back to my house. I had stopped at a light on West 45th Street, when my pal laughingly said, ‘Austin is such a hippie town.’”

A rusty Volkswagen Beetle pulled up to their left.

“I glanced over and saw that both guys in it had hair down their backs,” Preece continues. “The fellow riding shotgun turned, checked us out, decided that we were cool, then with surgical precision lifted a roach clip to his lips and took a hit. That moment was so perfect, my buddy and I could only stare at each other, speechless.”

Preece thinks many such events from the 1970s paved the way for Austin as we know it now.

“Like the incident at that stop light, the counterculture that had been brewing here in the previous decade turned to the establishment,” he says. “Both sides took a look at each other, and decided that, yeah, they could co-exist.”