AP White House Correspondent
WASHINGTON (AP) -- Declaring "our journey is not complete," President Barack Obama took the oath of office for his second term before a crowd of hundreds of thousands Monday, urging the nation to set an unwavering course toward prosperity and freedom for all its citizens and protect the social safety net that has sheltered the poor, elderly and needy.
"Our country cannot succeed when a shrinking few do very well and a growing many barely make it," Obama said in his relatively brief, 18-minute address. "We believe that America's prosperity must rest upon the broad shoulders of a rising middle class," he added, echoing his calls from the presidential campaign that catapulted him to re-election.
The president declared that a decade of war is ending, as is the economic recession that consumed much of his first term.
The inaugural fanfare spread across the capital Monday, with an inaugural parade down Pennsylvania Ave. and two glitzy inaugural balls. The president also lunched with lawmakers in the Capitol following his address.
Before diving into the afternoon celebrations, Obama previewed an ambitious second-term agenda, devoting several sentences to the threat of global climate change and saying that failure to confront it "would betray our children and future generations." Obama's focus on climate change was notable given that he barely dealt with the issue in his first term.
In an era of looming budget cuts, he said the nation has a commitment to costly programs such as Medicare, Medicaid and Social Security. "These things do not sap our initiative, they strengthen us," he said.
Sandwiched between the bruising presidential campaign and relentless fiscal fights, Monday's inaugural celebrations marked a brief respite from the partisan gridlock that has consumed the past two years. Perhaps seeking a fresh start, Obama invited several lawmakers to the White House for coffee before his speech, including the Republican leaders with whom he has frequently been at odds.
Among then was the Senate's top Republican, Mitch McConnell of Kentucky. In a statement following Obama's swearing-in, McConnell said the president's second term represented "a fresh start when it comes to dealing with the great challenges of our day."
Looking ahead to those challenges, Obama implored Congress to find common ground over the next four years. And seeking to build on the public support that catapulted him to the White House twice, the president said the public has "the obligation to shape the debates of our time."
"Not only with the votes we cast, but with the voices we lift in defense of our most ancient values and enduring ideals," Obama said.
Moments earlier, Obama placed his hand on two Bibles -- one used by the Rev. Martin Luther King Jr. and the other by Abraham Lincoln -- and recited the brief oath of office. Michelle Obama held the Bibles, one on top of the other, as daughters Malia and Sasha looked on.
Vice President Joe Biden was also sworn in for his second term as the nation's second in command. Former Presidents Bill Clinton and Jimmy Carter, several Cabinet secretaries and dozens of lawmakers were on hand to bear witness to history.
Monday's oaths were purely ceremonial. The Constitution stipulates that presidents begin their new terms at noon on Jan. 20, and in keeping with that requirement, Obama was sworn in Sunday in a small ceremony at the White House. Because inaugural celebrations are historically not held on Sundays, organizers pushed the public events to Monday, the same day the nation marked the late civil rights leader King's birthday.
Obama soaked in the history on a day full of traditions as old as the Republic. Gazing over the crowd before retreating into the Capitol, he said "I want to take a look, one more time. I'm not going to see this again."
After a stunning sunrise, the weather for the swearing-in and parade was chilly -- upper 30s rising into the lower 40s -- and overcast.
Once the celebrations subside, Obama will be confronted with an array of pressing priorities: an economy still struggling to fully a recover, the fiscal fights with a divided Congress, and new threats of terrorism in North Africa. The president has also pledged to tackle immigration reform and stricter gun laws in the wake of the school shootings in Newtown, Conn., -- sweeping domestic reforms that will require help from reluctant lawmakers.
Obama is also facing fresh concerns about terrorism in North Africa. In the midst of the inaugural celebrations, a U.S. official said two more Americans died in Algeria, bringing the U.S. death toll from a four-day siege at a natural gas plant to three. Seven Americans survived, the official said.