DALLAS (AP) — In a rare reunion, the five living American presidents gathered in Dallas Thursday to honor one of their own at the dedication of the George W. Bush Presidential Center.

The presidents — Bush, Barack Obama, Bill Clinton, George H.W. Bush and Jimmy Carter — were cheered by a crowd of former White House officials and world leaders as they took the stage together to open the dedication. They were joined on stage by their wives — the nation's current and former first ladies — for the outdoor ceremony on a sun-splashed Texas morning.

The leaders were putting aside the profound ideological differences that have divided them for years for a day of pomp and pleasantries. For Bush, 66, the ceremony also marked his unofficial return to the public eye four years after the end of his deeply polarizing presidency.

Each of the presidents was to make brief remarks at the ceremony.

In a reminder of his duties as the current Oval Office inhabitant, Obama planned to travel to Waco in the afternoon for a memorial for victims of last week's deadly fertilizer plant explosion.

Presidential politics also hung over the event. Ahead of the ceremony, former first lady Barbara Bush made waves by brushing aside talk of her son, former Florida Gov. Jeb Bush, running for the White House in 2016.

"We've had enough Bushes," said Mrs. Bush, the wife of George H.W. Bush and mother of George W. Bush. She spoke in an interview with NBC's "Today" show.

Yet George W. Bush talked up the presidential prospects of his brother in an interview that aired Wednesday on ABC.

"He doesn't need my counsel, because he knows what it is, which is, 'Run,'" Bush said.

Key moments and themes from George W. Bush's presidency — the harrowing, the controversial and the inspiring — would not be far removed from the minds of the presidents and guests assembled to dedicate the center, where interactive exhibits invite scrutiny of Bush's major choices as president, such as the financial bailout, the Iraq War and the international focus on HIV and AIDS.

On display is the bullhorn that Bush, near the start of his presidency, used to punctuate the chaos at ground zero three days after 9/11. Addressing a crowd of rescue workers amid the ruins of the World Trade Center, Bush said: "I can hear you. The rest of the world hears you. And the people who knocked these buildings down will hear all of us soon."

"Memories are fading rapidly, and the profound impact of that attack is becoming dim with time," Bush told The Associated Press earlier this month. "We want to make sure people remember not only the lives lost and the courage shown, but the lesson that the human condition overseas matters to the national security of our country."

More than 70 million pages of paper records. Two hundred million emails. Four million digital photos. About 43,000 artifacts. Bush's library will feature the largest digital holdings of any of the 13 presidential libraries under the auspices of the National Archives and Records Administration, officials said. Situated in a 15-acre urban park at Southern Methodist University, the center includes 226,000 square feet of indoor space.

A full-scale replica of the Oval Office as it looked during Bush's tenure sits on the campus, as does a piece of steel from the World Trade Center. In the museum, visitors can gaze at a container of chads — the remnants of the famous Florida punch card ballots that played a pivotal role in the contested 2000 election that sent Bush to Washington.

Former first lady Laura Bush led the design committee, officials said, with a keen eye toward ensuring that her family's Texas roots were conspicuously reflected. Architects used local materials, including Texas Cordova cream limestone and trees from the central part of the state, in its construction.

From El Salvador to Ghana, Bush contemporaries and former heads of state made their way to Texas to lionize the American leader they served alongside on the world stage. Among the foreign leaders set to attend were former British Prime Minister Tony Blair, former Israeli Prime Minister Ehud Olmert and former Italian Prime Minister Silvio Berlusconi.

The public look back on the tenure of the nation's 43rd president comes as Bush is undergoing a coming-out of sorts after years spent in relative seclusion, away from the prying eyes of cameras and reporters that characterized his two terms in the White House and his years in the Texas governor's mansion before that. As the library's opening approached, Bush and his wife embarked on a round-robin of interviews with all the major television networks, likely aware that history's appraisal of his legacy and years in office will soon be solidifying.

An erroneous conclusion that Iraq had weapons of mass destruction, a bungling of the federal government's response to Hurricane Katrina and a national debt that grew much larger under his watch stain the memory of his presidency for many, including Obama, who won two terms in the White House after lambasting the choices of its previous resident. But on Wednesday, Obama staunchly defended Bush's commitment to America's well-being while addressing Democratic donors.

"Whatever our political differences, President Bush loves this country and loves his people and shared that same concern, and is concerned about all people in America," Obama said. "Not just some. Not just those who voted Republican."

There's at least some evidence that Americans are warming to Bush four years after he returned to his ranch in Crawford, even if they still question his judgment on Iraq and other issues. While Bush left office with an approval rating of 33 percent, that figure has climbed to 47 percent — about equal to Obama's own approval rating, according to a Washington Post-ABC News poll released ahead of the library opening.

Bush pushed forcefully but unsuccessfully for the type of sweeping immigration overhaul that Congress, with Obama's blessing, is now pursuing. And his aggressive approach to counterterrorism may be viewed with different eyes as the U.S. continues to be touched by acts of terrorism.

Although museums and libraries, by their nature, look back on history, the dedication of Bush's library also offers a few hints about the future, with much of the nation's top political brass gathered in the same state.

Clinton's wife, Hillary Rodham Clinton, stoked speculation about her own political future Wednesday in a Dallas suburb when she delivered her first paid speech since stepping down as secretary of state earlier this year. Republican Gov. Chris Christie of New Jersey, another potential 2016 contender, flew to Texas to take part in the library dedication.

Obama, too, may have his own legacy in mind. He's just a few years out from making his own decision about where to house his presidential library and the monument to his legacy.