Beaming before an exultant sea of people, President Barack Obama on Monday reveled in his distant Irish ancestry, offering spirited thanks from tens of millions of Americans who trace their own connections to Ireland. With his wife, Michelle, at his side, the president said: "We feel very much at home."

In a speech devoted as much to personal pride than overt politics, Obama told many thousands gathered in central Dublin that he had come to reaffirm the bonds of affection between the United States and Ireland. "There's always been a little green behind the red, white and blue," he said to cheers.

Obama spoke shortly after he had downed a pint of Guinness in tiny Moneygall, the small Irish village where his great-great-great grandfather once lived and worked as a shoemaker. It was an improbable and memorable pilgrimage for America's first black president into his Irish past, and Obama soaked it in.

"My name is Barack Obama, of the Moneygall Obamas," the president said. Then, playing off the popular Irish spelling of surnames _ O'Bama _ the president said, "I've come home to find the apostrophe that we lost somewhere along the way."

The president struck a more serious tone in marking the adversity of Ireland's history and current times, celebrating a country that shares a resilient success with America. "We're peoples, the Irish and Americans, who never stop imaging a better future, even in bitter times," Obama said.

Obama addressed roughly 30,000 people packed into College Green for an open-air event headlined by Obama and billed as a celebration of Irish culture.

Irish Prime Minister Enda Kenny introduced the Obamas to a crowd that made clear its desire that he step aside for their distinguished guest as quickly as possible. "Obama!" they chanted as Kenny, undeterred, continued to proclaim the inspiration of Obama's life story.

"The 44th president is different, because he doesn't just speak about the American dream. He is the American dream!" Kenny said before surrendering the podium to thunderous cheers.

Obama is on a six-day, four-country tour of Europe.