WASHINGTON – President Obama officially took the oath of office for a second term at a private White House ceremony Sunday as hundreds of thousands of people from across the country – Buffalo included – gathered in the nation’s capital to celebrate.

With first lady Michelle Obama and his children looking on in the Blue Room of the White House, the president laid his hand on a Bible used for generations by the family of his wife – a descendent of slaves – and took the oath from Chief Justice John G. Roberts Jr. at 11:55 a.m.

Clad in a sober dark suit and tie, the president then turned to his younger daughter, Sasha, 11, and told her: “I did it.”

The brief late-morning ceremony fulfilled the constitutional requirement that the oath be taken before noon Jan. 20.

The grand inaugural ceremony outside the Capitol, the parade and the official inaugural balls were delayed until today because Jan. 20 fell on a Sunday.

But the celebrations started early, with tens of thousands of people crowding the streets of the capital, many guests from Buffalo gathering for a Democratic Party reception and the New York State Society sponsoring its own inaugural ball Sunday evening.

Overall, though, the second Obama inaugural was set to be a low-key affair compared with his first, with fewer than half as many people in attendance, no inaugural concert and only two official balls – the fewest since the Eisenhower administration six decades ago.

The low-key tone was set with the White House ceremony. On hand to witness the event were not only the first lady and daughter Sasha, but older daughter Malia, 14; Obama’s sister, Maya Soetoro-Ng, and her family; Michelle Obama’s mother, Marian Robinson; and the first lady’s brother, Craig Robinson. A press pool consisting of a handful of reporters, photographers and camera operators covered the event.

Four years after stumbling over the oath at the outdoor inauguration, forcing a repeat at a private White House event a day later, the Buffalo-born chief justice executed the oath flawlessly Sunday. He, and Obama, will repeat the oath at today’s public event on the West Front of the Capitol.

Under the Constitution, the president must say the oath as follows: “I do solemnly swear [or affirm] that I will faithfully execute the office of president of the United States, and will to the best of my ability preserve, protect and defend the Constitution of the United States.”

Vice President Biden took a similar oath earlier Sunday at his official residence. Supreme Court Justice Sonia Sotomayor, the first Hispanic on the court, became the first Hispanic to swear in a vice president.

Obama and Biden began their day in sparkling sunshine at Arlington National Cemetery, where they laid a wreath at the Tomb of the Unknowns.

From there, Obama and his family traveled to Sunday services at Metropolitan African Methodist Episcopal Church in memory of the Rev. Martin Luther King Jr., the civil rights leader whose name Obama often evokes and whose national holiday coincides with this year’s public inauguration celebration.

At the service, the Rev. Jonathan V. Newton asked God to prepare Obama for tough struggles ahead, “because sometimes enemies insist on doing it the hard way.”

The Obama presidency to date has been an era of tough struggles, and there is no reason to believe that will change in his second term.

Elected four years ago on a promise to heal partisan divisions, Obama instead immediately found himself confronting the greatest economic crisis since the Great Depression. And now, an entire presidential term later, the unemployment rate remains at 7.8 percent, exactly where it was when he took the oath of office in 2009.

Yet as much as Obama’s term was one of painfully slow economic recovery, it was also one of significant accomplishment. Achieving a goal that had eluded presidents for decades, Obama won passage of a health care overhaul, the Affordable Care Act. And achieving a goal that had eluded his predecessor, George W. Bush, Obama approved a raid that led to the death of Sept. 11 terrorist mastermind Osama bin Laden.

Obama begins his second term with an approval rating – 51.9 percent in the latest average by – that reflects the divided nation he leads. His second term opens with major battles expected with Republicans in Congress over budget issues, gun control and immigration.

If tradition holds, though, Obama will not stress those battles in his inaugural address today. Such speeches typically aim to be more unifying and uplifting, meaning that Obama is more likely to challenge Republicans for action in his State of the Union address Feb. 12.

But many Democrats, such as Erie County’s Democratic county executive, Mark C. Poloncarz, are hoping for something bold from the president. “I think he needs to say. ‘This is what we, as a country, need to do,’ ” he said. “I’d like him to say, ‘In four years, this is what we can accomplish.’ ”

And even though the nation remains deeply divided between red and blue, early signs were that this inauguration, like all such events, is likely to be inspiring.

Although there will be only two official inaugural balls tonight – down from 10 four years ago – states and special interests made up for it by scheduling more than four dozen unofficial galas, which started over the weekend.

Meanwhile, there were countless smaller celebrations, too. Red, white and blue bunting adorned the front of some of the city’s many bars, where lines of revelers were already gathering Sunday night, and Democrats from Erie County gathered at one of them, the Beacon Bar and Grill just north of downtown, to celebrate on Sunday evening.

Jeremy J. Zellner, the Erie County Democratic chairman, said the 100 or so Democratic activists from the county were every bit as excited for Obama’s second inauguration as they were for the first.

“I feel like we’re at the halftime of a football game,” Zellner said. “Now the president is going to have to go out and win in the second half, his second four years.”

Others were thinking not so much about politics, but about the awe-inspiring sight of 800,000 people gathered on the National Mall to celebrate Obama’s second inauguration.

“This is my first inauguration, and it’s very, very exciting,” said Dionne Wallace, 41, of Buffalo. “I just want to feel that vibe of everyone being together.”

Others, of course, wanted to feel the party vibe that envelops Washington every four years.

For example, about 250 people gathered at the Fairmont Hotel on Sunday night for the New York State Society’s first inaugural ball.

Long before the dancing was to begin and long before a mechanical cart bearing dessert and a miniature Statue of Liberty was set to make its way through the crowd, food producers from across the state showed off their products at the ball.

James T. Malley, a Buffalo teacher who founded Lewiston Jellies, proudly showed off his products, all of them made from fruit harvested in the state. “Someone saw my products at a store and called me and said, ‘Do you want to come down for the inaugural?’ ” Malley said.

Malley has to get back home and isn’t going to the inaugural, but Mary Ann Hess, of Niagara Falls, owner of Niagara’s Honeymoon Sweets, was lucky enough to score tickets through a friend.

Showing off her chocolate medallions and edible picture frames, she captured the mood of many, saying: “I am so excited. This is the first time I’ve ever done anything like this.”

News wire services contributed to this report. email: