It was one for the ages — all ages.
Thousands of spectators young and old lined up six-deep along a Long Island roadway Sunday in a massive celebration of the Nassau County Police Department’s 100th anniversary.
Nearly 2,000 marchers — including a large contingent of motorcycle cops — traveled the 1-mile route on Wantagh Highway to mark the centennial for what County Executive Bruce Blakeman billed as “a super block party” when he announced the event last month.
“Thank you, thank you!” lifelong Wantagh resident Rose Lule shouted at the procession.
“Absolutely I’m grateful to them,” Lule, 65, told The Post. “Do you think this would be the safest place to live like it is without them? We’ve been here 56 years, and they’ve always been very good to us.”
Nearby, two youngsters — Max Zimmer and his buddy, Sean Joseph Nichols — dashed out onto the route to pet a police K-9 marching in the parade.
“I’m pretty sure they’re not supposed to do that,” mom Marcella Zimmer quipped.
The boys were thrilled.
“The best part of the parade was the dogs! Even better than the tanks!” Sean said.
Max said, ”Yeah, petting the dogs was the best part.”
Meanwhile, marchers tossed NCPD balls, frisbees and t-shirts to anxious youngsters along the route.
The hometown celebration paid special honor to the original 55-member force that launched the Nassau department 100 years ago, with half the cops on motorcycle duty.
Last year, the county department had about 2,600 officers, or the 12th largest police force in the country, bigger than cities such as Boston and Baltimore.
Among the proudest spectators at Sunday’s celebration feting the Long Island department were Susan and Tom Shutowich of East Northport, who have a son on the Nassau County SWAT team and another who is a Suffolk County court officer.
“I’m proud of our boys, and I’m also proud of all of them out here today,” said Susan Shutowich, 75. “I’m proud of every one of them out here today because it’s a really important job, and the public knows it.
“Ask people how important these are when someone’s calling for help from these guys!”
The highlight Sunday was a vintage Harley Davidson Model JD police bike, the same model mounted by the first cops in 1925 — although it did show its age.
The old motorcycle stalled several times along the parade route, forcing the pretend “prisoner” riding in the side car to get out to restart the bike each time.
“Move it, move it!” Police Commissioner Pat Ryder yelled. “Let’s go, you’re holding up the parade!”
Happily, the faux inmate, highway patrol civilian tech Curt Gruber, got the motor going each time.
“It worked perfect, road-perfect, when I got it over here before the parade started,” said Officer Michael Vonnes, who was riding the old bike. “Then of course, I was nervous, everybody watching, and of course!”