Chief Justice John Roberts was ushered into the Map Room of the White House on Wednesday night to re-administer the oath of office to President...

WASHINGTON — Chief Justice John Roberts was ushered into the Map Room of the White House on Wednesday night to re-administer the oath of office to President Obama because the original oath Tuesday had a word out of sequence.

White House spokesman Robert Gibbs said the move was made out of “an abundance of caution” in consultation with White House Counsel Greg Craig. Obama’s second swearing in, devoid of pomp, took place at 7:35 p.m. in the presence of a few aides and a news pool. The chief justice was wearing a court robe. “Are you ready to take the oath?” Roberts said. “I am,” Obama said, “and we’re going to do it very slowly.”

It capped a packed first full day for the 44th president that began at 8:35 a.m., when he entered the Oval Office — now his.

In the top desk drawer lay an envelope inscribed, “To: 44, From: 43.” He sat alone and read that traditional private note from his predecessor, President Bush.

Another new-president tradition dating to George Washington: The Obamas attended a prayer service at Washington’s National Cathedral.

He also celebrated a political victory as his former presidential primary rival, Hillary Rodham Clinton, was confirmed by the Senate as secretary of state with a vote of 94-2.

He appeared to be moving full steam ahead on plans to halt military-commission trials at Guantánamo Bay and to close the detention camp within a year. After Tuesday’s inauguration, he ordered a 120-day halt to military tribunals there.

Obama also found time to call four Middle Eastern leaders Wednesday morning: Egyptian President Hosni Mubarak, Israeli Prime Minister Ehud Olmert, Jordan’s King Abdullah II and Palestinian Authority President Mahmoud Abbas.

White House spokesman Robert Gibbs said Obama thought it was important “on his first day in office to communicate his commitment to active engagement in pursuit of Arab-Israeli peace.”

In the afternoon, the first couple greeted visitors to an open house designed to signal a White House accessible to the general public. Two hundred people won invitations that aides said were distributed on a first-come, first-served basis.

“Welcome, enjoy yourself,” Obama told one visitor. “Roam around. Don’t break anything.”

Obama announced at a swearing-in ceremony for White House staff and Cabinet officials that he would freeze the pay of White House employees who make more than $100,000 a year. He told his senior staff that given the economic climate, “it’s what’s required of you at this moment.”

He signed two executive orders and three memorandums to implement the pay freeze, ethics and public-records changes.

The ethics order prohibits executive-branch employees from accepting gifts from lobbyists. It prohibits anyone who leaves the administration from lobbying the executive branch “for as long as I am president,” Obama said. It also precludes former lobbyists hired by his administration from dealing with agencies on matters they lobbied about for two years.

A second order revokes an executive order signed by Bush in 2001 that limited release of former presidents’ records, and replaces it with new language aimed at more transparency. Obama’s order could expand public access to the records of Bush and former Vice President Dick Cheney, as well as other former leaders, said Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists.

“It’s extraordinary that a new president would address this issue on his first full day in office,” Aftergood said. “It signifies the great importance he attaches to open, accountable government. The new order suggests President Obama will take a narrow view of executive privilege and assert it in a much more limited way than what we’ve seen in the recent past.”

Bush’s order gave former presidents broad ability to claim executive privilege and to designate others — including family members who survive them — to exercise that privilege. Obama’s new order gives ex-presidents less leeway, Aftergood said, and revokes the survivors privilege.

Another Obama memo issued Wednesday appears to rescind a 2001 memo by Bush’s then-Attorney General John Ashcroft giving agencies broad legal cover to reject public-disclosure requests.

“For a long time now, there’s been too much secrecy in this city,” Obama said. “This administration stands on the side not of those who seek to withhold information but with those who seek it to be known.”

Obama met with his economic advisers, and House Republicans asked him for a meeting as soon as today to talk about their party’s competing economic-stimulus plan. And he met in the Situation Room with his defense secretary, chairman of the Joint Chiefs of Staff and others to discuss Iraq and national security.

Obama has said that on his first day he’d ask military officials for a plan to withdraw combat troops from Iraq over a 16-month period and redeploy some to Afghanistan.

Correspondents Marisa Taylor, William Douglas and David Lightman contributed. Includes material from the Chicago Tribune.