WASHINGTON -- President Obama wrapped himself and his White House in St. Patrick's Day celebrations, claiming an Irish ancestry to Ireland's leader and joking to Congress that his genealogy could have helped him as a once-unknown Chicago politician.
White House fountains and sparkling wine both ran green on a day when Obama courted Ireland's prime minister and political leaders from Northern Ireland. As Obama sought to tamp down violence in Northern Ireland, he announced Tuesday a key campaign backer Dan Rooney, owner of the Pittsburgh Steelers football team, as his choice to fill the post of U.S. ambassador to Dublin.
"Not all Americans are Irish, but all Americans support those who stand on the side of peace and peace will prevail," Obama told Prime Minister Brian Cowen in the Oval Office, praising the two countries' deep ties.
The president also met with Northern Ireland's First Minister Peter Robinson, a Protestant, and his Catholic deputy, Martin McGuinness, in a less high-profile gathering in his national security adviser's office. Tensions are high in Northern Ireland, where Irish Republican Army splinter groups killed two soldiers and a police officer this month in the first attacks of their kind since 1998, when the landmark Good Friday Agreement was reached.
From appearance to agenda, the White House was in an unmistakable Irish mood. The fountains on the White House's North and South lawns were dyed green, a nod to the Obamas' hometown of Chicago where the city marks the national holiday of Ireland by dyeing the river green.
On tap for evening festivities -- which Obama described as "rambunctious" to East Room guests -- was green sparkling wine from a California vineyard.
The Irish guests returned to the White House for a cocktail reception Tuesday night. Pulitzer Prize-winning poet Paul Muldoon from Northern Ireland was to be featured. The White House also invited Maggie McCarthy, a traditional Irish dancer and musician from Cork, and the vocal group Celtic Thunder. The Shannon Rovers, the official pipe band of Chicago's St. Patrick's Day festival, also were set to perform.
Obama encouraged the Irish guests, senior members of his administration and members of Congress to stay as long as they liked. By midevening, the crowd packed the mansion's first floor and already were boisterous, with conversations elsewhere in the building echoing over the president's remarks.
Obama joked about the free-flowing bar and warned his guests not to wear lampshades on their heads in front of the cameras. He later went off his remarks to get laughs about Ireland's popular stout.
"Guinness tastes very different in Ireland," Obama said. "It is much better. You guys are keeping the good stuff for yourselves."
Elsewhere in the United States, other cities and towns honored Ireland with their own signature celebrations, taking a break from worrying about the global economy to enjoy a day of shamrock-themed frivolity.
Organizers predicted 200,000 participants -- and as many spectators -- would be along New York's Fifth Avenue for the city's 248th St. Patrick's Day parade.
Many cities with big Irish communities, like Boston and Chicago, had their celebrations over the weekend.
The New York St. Patrick's Day Parade started in 1762 as a modest foot parade, and still shuns commercial aspects like floats or cars.
The parade goes past Saint Patrick's Cathedral at 50th Street and continues up to the American Irish Historical Society at 86th Street. It is led by a unit of soldiers -- the "Irish Infantry" -- and is officially sponsored by the Ancient Order of Hibernians.
Holly Lopez, a nurse from Buffalo, New York, stood in the dozen-deep Manhattan crowd wearing a temporary shamrock tattoo, green feather necklace, an Irish flag in her cleavage and -- she said -- green underwear.
In Portland, Maine, 75 people greeted the day with an icy plunge in the Atlantic Ocean, charging into the 37-degree (2.78-Celsius) water at a beach and celebrating with a Guinness afterward.
At the White House, Obama and his aides pushed to salvage a peace in Northern Ireland.
Two soldiers were fatally shot on March 7 and a policeman murdered two days later.
Washington condemned the deaths as senseless acts of political obstruction aimed at destroying the stability in Northern Ireland and supported leaders who urged restraint. The attacks are the first of their kind since 1998, when the landmark Good Friday Agreement was reached.
Obama said it was no surprise that the opponents of a peace would try to undo it.
"The real question was this: When tested, how would the people of Northern Ireland respond?" Obama said in one of his appearances with Cowen. "And now we know the answer. They responded heroically. They and their leaders on both sides have condemned this violence and refrained from the old partisan impulses."
Administration aides have singled out Cowen, Robinson and McGuinness as leaders who have resisted partisan reactions to a series of killings in Northern Ireland that threatens a decade's break in violence.
Obama and the Irish leaders also attended a Capitol Hill luncheon celebrating the holiday. Obama, House Speaker of Representatives Nancy Pelosi and Cowen paid tribute to Sen. Edward M. Kennedy, who is being treated for brain cancer and was unable to attend. Cowen said Kennedy was "our most special Irishman."
The president laughed that the lunch as "a tradition in which Democrats and Republicans put aside partisanship and unite around one debate only -- who is more Irish than whom?"
Obama joined the contest.
"People help you discover a lot about yourself when you're running for president. As has been mentioned, it was brought to my attention last year that my great-great-great grandfather on my mother's side hailed from a small village in County Offaly," Obama said. "Now, when I was a relatively unknown candidate for office, I didn't know about this part of heritage, which would have been very helpful in Chicago. So I thought I was bluffing when I put the apostrophe after the O. I tried to explain that 'Barack' was an ancient Celtic name."
Obama's ancestor came from the village of Moneygall. County Offaly is in the southeastern province of Leinster.
Earlier, Obama tapped Rooney for the ambassadorship. A lifelong Republican, the 76-year-old Rooney endorsed Obama during Pennsylvania's contentious Democratic primary last year and campaigned for him throughout the election. The president returned the favor by nominating him to the ambassador post, a move that had been the subject of almost fever-pitch speculation in Irish circles in recent days.