A tropical downpour overnight failed to dampen spirits as hundreds gathered in a field at Obama’s late father’s village to watch the results relayed to a big screen.
Then came the news they were waiting for: Obama had won.
"We are going to the White House! We are going to the White House!" relatives sang at the top of their voices as they danced around the family’s modest homestead, pausing only to hug each other and hoist small children into the air.
Well-wishers, family members and armies of local and foreign journalists have descended on Kogelo, the tiny village in western Kenya where Obama’s 87-year-old grandmother lives.
"We haven’t slept all night," Biosa Obama, Obama’s 39-year-old sister-in-law told Reuters, dancing on the spot. "I don’t know what to say. This is just too amazing."
Nearby, a villager walked past wearing a huge top hat made of newspaper clippings of Obama’s picture.
Since 2004, when Obama was running for the Senate in Illinois, the Harvard-trained lawyer and civil rights activist has enjoyed rock star status in the east African nation.
Born in Hawaii to a white mother from Kansas and a Kenyan father, Obama is idolised by many the way the Irish saw U.S. President John F. Kennedy in the 1960s: as one of their own who succeeded beyond their wildest dreams.
Babies have been named after him, drinkers knock back "Senator" beers in his honour, pop stars sing his praises and "Obama: The Musical" opened in the capital Nairobi on Sunday.
Kenyan President Mwai Kibaki declared Thursday a national holiday to let Kenyans celebrate Obama’s success.
"We the Kenyan people are immensely proud of your Kenyan roots. Your victory is not only an inspiration to millions of people all over the world, but it has special resonance with us here in Kenya," Kibaki said in a statement.
Many Africans fervently hope his victory will mean more U.S. support for local development and an improvement in living conditions for the majority on the world’s poorest continent.
But analysts have cautioned that Obama will be able to do little to bring tangible benefits to Africa, and that he does not have a strong track record of interest in the continent.
For now, relatives in Kenya are still trying to take it all in — and planning for his first visit on Air Force One.
"It’s breaking news, he’s won," said his half-brother Sadiq Obama. "As you can see, everyone is happy – I’m ecstatic."