Muhammadu Buhari, who won the election in March, was inaugurated in the capital of Abuja. Outside the stadium venue, drummers and dancers gathered. So did dignitaries.
Crowds clapped while others used brooms to sweep to the beat, a reference to Buhari's campaign slogan, "new broom."
Hundreds of miles away in Lagos, Faruk Mohammed, 30, watched the exchange of power with pride.
"It's amazing ... the closest feeling I can compare it to is when a child graduates from university, it's a collective feeling of pride," he said by phone. "As a nation, that feeling that your vote counts is one of great pride. That the democratic institution has been restored."
Though Mohammed didn't vote -- thinking his vote wouldn't count in a nation riddled with a history of coups -- he said this day restored his faith in Nigeria's democracy.
"If an election was held tomorrow, I'd be the first one to vote," he said.
Long to-do list
Buhari takes over from Goodluck Jonathan, inheriting a nation with a stubborn militant insurgency and lingering fuel shortages
, a paradox for one of the world's largest oil producers.
"Today marks a triumph for Nigeria and an occasion to celebrate her freedom and cherish her democracy," Buhari said in his inaugural address.
He thanked Jonathan for setting the precedent for a peaceful transfer of power, and also gave credit to voters.
"At home, we face enormous challenges," Buhari said. "Insecurity, pervasive corruption, the hitherto unending and seemingly impossible fuel and power shortages are the immediate concerns. We are going to tackle them head on. Nigerians will not regret that they have entrusted national responsibility to us. We must not succumb to hopelessness and defeatism. We can fix our problems."
Buhari also recognized those who supported him online.
"I thank those who passionately carried the campaign on social media. I belong to everybody. I belong to nobody," he said via Twitter.
Mohammed said the new President has a lot of work cut out for him.
"He has to assemble a credible team of performers, of technocrats, put a structure in place to start working on the promises he made," he said. "I hope he justifies the kind of faith we have put in him."
Buhari has ruled before
Leadership is nothing new for Buhari. The former general was among military strongmen who dominated Nigeria decades ago.
A military coup brought him to power in 1983, and another military coup toppled him two years later.
Buhari's regime was known for its "war on indiscipline," which critics say was marred by human rights abuses.
Before the election, African affairs analyst Ayo Johnson said Buhari's military background may be what voters need to feel safe from the deadly Boko Haram
"Many Nigerians will not forget he was a military leader, during a dictatorship," Johnson said. "Or maybe they will feel that they need a military leader to address fundamental problems such as terrorism."
This year alone, the Islamist extremists have killed at least 1,000 civilians, mostly in the nation's northeast, where they operated freely, Human Rights Watch says.
Their bloody reign of terror put security -- along with corruption and the economy -- at the top of the election agenda.
Buhari campaigned as a born-again democrat to allay fears about his strict military regime while stressing the need to focus on security.
His first priority, Mohammed said, is fighting the nation's endemic corruption, which has crippled the oil industry.
This year's presidential race was his fourth attempt at leadership since he was ousted from power in 1985.
Though his military past haunted him during the campaign, voters overlooked it.
Buhari has admitted to abuses committed during his military leadership but said he was being judged too harshly and can transition into a democratic government.
His leadership under a democratic system paves the way for a new chapter, one he celebrated with allies from near and far.
U.S. Secretary of State John Kerry
joined other world leaders at the event, including South African President Jacob Zuma.
"Glad to be back in Nigeria and honored to be leading the U.S. delegation for inauguration," Kerry tweeted.
Zuma said his trip will present an opportunity
to discuss relations between Nigeria and South Africa, both considered powerhouses in the continent.
After the inauguration, Buhari's convoy headed to the presidential residence. Crowds in Abuja lined the streets, cheering and chanting his name all over again.