Story and images by Alex Tétreault, with files from Mike De Souza and The Canadian Press.
With the sun peaking through a soggy Saturday morning in Ottawa, they began to roar in approval when they spotted a pair of famous special guests.
"The rain you can blame on the Irish," U2 frontman Bono said with a chuckle, drawing some laughter and appreciation from the crowd of thousands who were lucky enough to get through intensive security screenings just in time for the opening act.
The media riser was less than 50 metres away from the stage, putting the performers at the edge of my lens' reach. I was standing elbow-to-elbow with a few dozen fellow photographers, cameramen and journalists who were on assignment either to document the milestone birthday or to analyze all of the achievements, regrets, failures and successes of Canada's history.
This was the scene on the front lawn of Parliament Hill in Ottawa as the country gathered to mark the 150th anniversary of Confederation, on July 1, 1867, when the British North American Act came into force, creating modern Canada.
For some, it was a grand celebration.
Others found themselves frustrated by thunder showers and the chaos of snaking lines in what CBC News described as an "absolute fiasco."
Thousands who made it in for the opening festivities had lined up in the early morning rain to get access to the site.
But most who showed up after 9 a.m. wound up stuck in the line-ups that took up several city blocks, hours later. Going around the grounds, I even chatted with some people who said they had waited over seven hours before making it through the security checkpoint.
And then there were the stories from people who said they waited for hours and gave up after realizing the "line" they were waiting in, was actually leading to nowhere.
But I also spotted a few who made it inside and found themselves playfully confronting a partially-flooded lawn.
And despite many positive images and messages, along with star power of special guests like Bono and The Edge from U2 as well as the Prince of Wales, there were still many who saw it as a painful reminder of Canada's colonial and racist history.
One day earlier, Sen. Murray Sinclair, who chaired the Truth and Reconciliation Commission, said he would be on hand for Canada 150 events as a gesture of reconciliation from the Indigenous perspective.
"Celebrate is not the right word," he told The Canadian Press. "I will be attending events."
This was a common theme addressed throughout the day as the crowd heard renewed calls to strive for reconciliation with Indigenous people.
The Truth and Reconciliation Commission had concluded, two years earlier, that Canada committed "cultural genocide" by forcibly separating Indigenous children from their parents and sending them to schools that existed from the 1840s until the 1990s in a "systematic and concerted attempt to extinguish the spirit of Aboriginal peoples."
Nearly 150,000 children suffered horrific abuse in the schools before they were shut down.
But many of the speakers, like Bono, also celebrated Canada's role as a world leader, noting its reputation for being a land of diversity and inclusion for immigrants.
"Myself and The Edge are here all the way from the north side of Dublin to salute you. We have a side gig playing weddings, funerals and Bar Mitzvahs, but this is our very first 150th birthday party. Is it not The Edge?"
"The Irish have been welcomed here for hundreds of years and still now. And from the famine, where we were in many respects refugees, to now where we arrive by choice, bringing ingenious little start-ups and approximately 17,165 Irish pubs."
The crowd roared in approval as Bono continued his monologue with The Edge beginning to strum the opening notes of U2's 1991 hit song: One.
"Whether you have just arrived from Syria or your roots go back thousands of years, this is your home and we are grateful guests in it," Bono continued. "When others build walls, you open doors. When others divide, your arms are open wide. Where you lead, others follow, and that's the real reason that The Edge and myself are here today."
He repeated the same message in French, before continuing.
"Together, we are stronger. Happy birthday."
Bono and The Edge's act came after hours of steady rain left huge puddles of water on the front lawn of Canada's Parliament.
The soggy weather eased up as the show began, heralding the arrival of the royal landau and Prime Minister Justin Trudeau.
The prime minister arrived with his family, greeting and shaking hands with some in the crowd before they were joined by Prince Charles and Camilla, escorted by a contingent of the RCMP's cavalry. They spoke with some Indigenous performers near the centennial flame before being whisked off to their seats to watch the show.
"Our past is far from perfect," Trudeau told the crowd as he opened the celebration, following a warm ovation.
"For centuries, Indigenous Peoples have been victims of oppression, from the time when the first explorers celebrated their discovery of the new world."
He urged the crowd to acknowledge the country's history and to confront its reality.
"We must educate ourselves and dedicate our efforts to progress," he said. "It is a choice we make not because of what we did, or who we were, but because of who we are."
The celebrations came after a few days of tense standoffs between Water Protectors from Northern Ontario who came to denounce centuries of occupation and colonization of Indigenous land in North America.
They had attempted to set up a teepee on Parliament Hill earlier in the week, but were initially stopped and detained by police. They later reached an agreement to move their set up onto the west side of the front lawn.
By the end of the week, the protesters received a visit from the prime minister and Sophie Grégoire Trudeau. And they delivered a message to Trudeau that they would hold the government to its promises to bring about reconciliation with Indigenous people.
For this rainy Saturday, the Water Protectors had lit a ceremonial fire about the size of a small campfire next to the teepee, a fire that was meant to burn for four days. I visited them in the morning to see if I could take some pictures.
But they promptly told me that they didn't want anyone from outside their circle to capture any images of the fire nor people around it, essentially negating any meaningful imagery. More protesters, seemingly alerted by my presence, moved to join the circle and block it from sight.
I turned away.
They also tried to deliver their message with all of the cameras watching as Trudeau and the royal landau arrived on seen. But the water protectors were held back and could not approach until the special guests had moved on.
Almost immediately after the dignitaries had moved to the front of the stage, the signs and banners of the protesters crowded near the Centennial Flame.
Prince Charles, who was wrapping up a visit to Canada with Camilla, appeared to recognize some of the tensions as he addressed the crowd.
He also showered the country with his own encouragement and praise.
"Ladies and gentlemen we should be clear and proud that we are celebrating a country that others look to for example — an example of fairness and inclusion of always striving to be better," he said on stage to applause.
And then he went on, cautiously weighing into the controversy.
"Around the world, Canada is recognized as a champion of human rights, as a peacekeeper, a responsible steward of the environment and natural resources and as a powerful and consistent example of diversity and the power of inclusion, with, if I may say so, Canada’s commitment to reconciliation with Indigenous peoples, demonstrating a remarkable determination to forge an ever-better society.”
The big party also brought some unfamiliar sights to Canada's calm and quiet capital city, briefly giving it the appearance of a military state.
The authorities had cordoned off a large block of downtown Ottawa using concrete barriers and heavy utility trucks and machinery, and the RCMP and Ontario Provincial Police agents were equipped with 5.56mm caliber carbines.
All of these measures were triggered in the wake of recent events in Europe when vehicles were used as weapons targeting large crowds. There were also special arrangements in place to accommodate the visit of Prince Charles and Camilla.
A few months earlier in Canada, a 27-year-old right-wing extremist and a self-described Donald Trump "fan" named Alexandre Bissonnette was charged with six counts of murder and five counts of attempted murder after a mass shooting on Jan. 29 that targeted Muslims who were praying in a Quebec City mosque.
But the extra security wasn't enough to stop many of the festive party-goers who were determined to make it close to the front of the stage, regardless of the hours spent waiting in the rain.
On the inside, Canada's star power was front and centre.
The opening celebration itself was hosted by Quebec singer and broadcaster Mitsou Gélinas and actor Sandra Oh. The line-up included performances by Buffy Sainte-Marie, Marie-Mai and Laurence Nerbonne, Patrick Watson, Walk Off the Earth as well as Marie-Josée Lord who performed the national anthem.
Canadian country singer Shania Twain and Federal Industry Minister Navdeep Bains were also on hand to introduce Canada's newest astronauts, Jen Sidey and Josh Kutryk from Alberta.
U2's Bono (Paul Hewson) and The Edge (David Evans) made their stop in Ottawa, in the middle of their Joshua Tree tour, to play one song, pro bono, for the celebration, before flying off to Cleveland for their evening show.
Canadian Heritage Minister Mélanie Joly, the lead federal cabinet minister responsible for Canada 150 festivities and events, estimated to be costing about $500 million, was also on hand to help open the event.
The sun even started to pierce through the clouds as the opening celebration ended, making way for the day long list of performers for the day, before it all wrapped up with fireworks late in the evening (after more downpours).
The prime minister's speech, described by The Canadian Press, as a forceful and enthusiastic celebration of the unique power and resilience of the Canadian character sparked a roar in the crowd.
It came moments after the roar of a single CF-18 that streaked over the Centre Block, drowning out the final notes of O Canada. But it was also hours before a spectacular fly-by of Canadian snowbirds.
Trudeau delivered a wide-ranging talk, addressing the crowd in both of Canada's official languages, speaking about building a better country and addressing challenges such as climate change. Like the others, he also highlighted diversity as a strength.
"We don't aspire to be a melting pot," Trudeau told the cheering crowd.
"We know true strength and resilience flows through Canadian diversity. Ours is a land of original peoples and of newcomers, and our greatest pride is that you can come here from anywhere in the world, build a good life and be part of our community."