At last, for a town once deprived of big league baseball for 33 summers, the hard relearning curve of fandom ends in autumn bliss. So let’s throw a parade! The long wait is done, over, finis, and your Nationals are World Series champs, rollicking through the giddy heart of Washington in a fleet of open-top buses Saturday as hundreds of thousands of red-clad revelers, a sea of the faithful, bellowed out love and thanks.

Three days after the team’s Game 7 road win over the Houston Astros gave the nation’s capital its first Series title in 95 years, a mile-long rolling victory celebration turned Constitution Avenue NW into a Canyon of Heroes in (of all places) Washington, which put aside impeachment for an afternoon of unbridled nonpartisan joy.

“It’s unbelievable,” pitcher Patrick Corbin declared. Someone had told him the crowd might number a million. “This many people showing up for this is special,” he said. “It’s still crazy to think we’re world champions.”

The cheering multitudes, packed along the avenue on a mild day of brilliant sunshine, then massed for a rally near the Capitol. These fans had weathered the early years of Nats futility when it seemed the team couldn’t hit or pitch or even spell (remember “Natinals”?) and later those four Octobers of murdered hopes. For the players, it was a party of beer-spraying and cork-popping.

After pitcher Max Scherzer’s rally speech, the public address system played the song “Calma,” one of the Nats’ many lucky charms, while infielder Brian Dozier, shirtless, picked up teammates and danced with abandon. “My wife’s going to kill me,” he said into a microphone before getting a piggyback ride around the stage.

At one point during the parade, General Manager Mike Rizzo brought the Commissioner’s Trophy to fans behind barricades, a cigar jutting from his mouth, trading high-fives with one hand while holding the trophy aloft with the other. Manager Dave Martinez also joined the fans, slapping every hand raised in his direction.

Far beyond the Beltway this baseball postseason, there was a notion that Nats fans are mostly K Street lobbyists and lawyers, Deep State functionaries or fat cats in the media-political industrial complex. (After the crowd at Game 5 of the Series jeered President Trump, a Fox News chyron read, “THE SWAMP BOOS AMERICA.”) Yet check out Jack Dwier, on break from a G Street construction crew.

He handed a parade vendor $50 in workingman’s dough for a couple of souvenir T-shirts and a sweater, which he couldn’t find at a sporting goods store.

“I went to Dick’s three times but they were all sold out,” said Dwier, 65, of Lake Ridge, Va., who has lived and groaned with his team — the ex-Montreal Expos — since it moved to Washington in 2005. He listened to the Series clincher on the radio, on the job.

In jeans and laborer’s boots, his white hair dangling in a ponytail and crowned with a World Series Nats cap, he said, “I’m not a bandwagoner.”

Like Dwier, Joe Shifflett, a 63-year-old home-renovation contractor and District native, grew up rooting for the old Washington Senators, winners of the city’s only previous World Series title, when Calvin Coolidge was in the White House.

Perched on a bench outside a museum in Saturday’s celebratory din, Shifflett thought of his father, dead 21 years, a combat veteran who was never the same after World War II, after horrors in Italy and France. He thought of ancient nights in RFK Stadium and long-gone Griffith Stadium and how much George Shifflett would have enjoyed these ’19 Nats. “One of the few times he seemed happy was at a baseball game,” the son recalled.

“He would have loved this.”

The first Senators franchise, champs of 1924, decamped to Minnesota in 1960, and the successor Senators, born the next year, departed for Texas after 11 seasons, leaving the District bereft of big league baseball for three decades-plus. Gifted with a new team, fans weathered seven summers of on-field ineptitude, giving way to autumns (2012, ’14, ’16, ’17) of soul-killing playoff eliminations, including three series that went the distance.

Not until this year did Washington win even one October round.

After Nationals principal owner Mark Lerner finished his remarks onstage, the rally segued into a “Baby Shark” singalong, a tribute to the team’s beloved toddler anthem. Players sheepishly joined in, with outfielder Gerardo Parra gripping a blue stuffed shark and thanking the crowd.

Tamara Cole, 53 and proud to be a die-hard Nats fan since way back in July, when she moved here from California, claimed her spot for the parade well before noon after arriving on the route in her motorized wheelchair. She bought a $5 “victory horn,” donned the “Bring It Home” beanie she got last week, then plugged a Nats-red audio speaker into the wheelchair’s battery. Soon her favorite oldies were blaring.

Shake, rattle and roll. …

“I tried to leave everything behind and start anew,” she said of her move from the West Coast. That included the San Francisco Giants gear she threw away.

A bandwagon-jumper? There were plenty like her on Constitution Avenue. Who cares?

“Everybody likes a good party,” Cole said.

Wherever you looked, there were miniature Nationals fans: babies in shark costumes napping despite the noise, boys and girls in Juan Soto jerseys, for the Nats second-year phenom. All along the parade route, kids were perched on their parents’ shoulders. This next generation of Nationals fans has only ever known the city with a baseball team.

Elizabeth Cavadel grew up in Philadelphia and has rooted for the Phillies most of her life. But Nationals fandom gripped her 6-year-old son, James, and when the two division rivals meet, theirs is a house divided.

James held a sign he made with sticks of wood and a Manila folder: “GO NATS!” He drew a shark in one corner, and a bat and a ball. “HOME RUN,” it read.

“I just like them,” was all he could think to say.

Record-wise, they were the third-worst team in baseball, ­19-31, as Memorial Day approached. The resurrection, 74-38 the rest of the way, was equal parts grit and summer magic, followed by the tightrope walk of October, when some nights they wobbled and maybe you figured, well, that’s it — again. But uh-uh. In Saturday’s sunshine, there they stood, 12-5 in the Big Month and pretenders no more, hoisting the Commissioner’s Trophy as thousands of rally-goers watched, alternately raucous and reverent.

“I got players telling me to watch my heart,” said Martinez, who was hospitalized late in the season for a coronary procedure. “I got fans screaming at me: ‘Your heart, Davey! Your heart, Davey!’ I’m going to tell you something: All this right here has cured this heart.”

And here you are in the afterglow, a bittersweet thought creeping in: Okay, now what?

“There were so many highs and lows, so many emotions,” said Jihad Abdus-Salaam, 71, who knows it’s over, fading already.

Goodbye “Stay in the Fight.” Goodbye Baby Shark and “clutch and drive” and cheap shades from Bubly. Goodbye “Let’s go 1-0 today.”

So long fan-fave Parra off the bench, probably.

Goodbye . . . Stephen Strasburg? Anthony Rendon? Although Strasburg is a good bet to be back, he was expected to invoke an opt-out clause in his contract by a Saturday night deadline, while Rendon became a free agent Thursday. Big stars, both, and it’s all about nine-figure money deals going forward.

“I personally think Rendon is going to stay,” said Albert Hubb, 60, a born Washingtonian, refusing to not be optimistic on a day like this. “If they get rid of Strasburg,” he said, “they might as well pack the team up and go home.”

There’s a saying in the cold-eyed business of baseball roster-building: Never fall in love with last year’s team. But that’s for management, not you. You have front pages to frame and commemorative magazines to hoard, tickets stubs to cherish and, one day real soon, an official World Series video to download and watch in the snow. You get to bask in this for a while — 3½ months, anyway. Pitchers and catchers don’t report to spring training until mid-February. No need to move on just yet.

“I’m going to ride this one until next year,” said Hubb. “And if we don’t win next year, we’ll try again.”