It was the 25th meeting between a Roman Catholic pope and a U.S. president, sessions that have spanned 89 years, five pontiffs and 11 American leaders.
Bush and Benedict share much common ground, particularly in opposing abortion, gay marriage and embryonic stem cell research.
But they disagree over the war in Iraq, the death penalty and the U.S. trade embargo against Cuba. Benedict also speaks for environmental protection and social welfare in ways that run counter to Bush policies.
A joint U.S.-Holy See statement hinted that Benedict brought up his concerns about the damage caused by punitive immigration laws. It said the leaders discussed "the need for a coordinated policy regarding immigration, especially their humane treatment and the well being of their families."
On Iraq, discussion steered away from the war itself to focus primarily on worries for the Christian minority in the Muslim-majority country, said White House press secretary Dana Perino.
Other topics included human rights, religious freedom, fighting poverty and disease in Africa, the Israeli-Palestinian dispute, Lebanon and terrorism.
"The two reaffirmed their total rejection of terrorism as well as the manipulation of religion to justify immoral and violent acts against innocents," the statement said.
It also said the leaders "touched on the need to confront terrorism with appropriate means that respect the human person and his or her rights," a reference Perino could not explain. Benedict has been critical of harsh interrogation methods, telling a meeting of the Vatican's office for social justice last September that, while a country has an obligation to keep its citizens safe, prisoners must never be demeaned or tortured.
One topic not mentioned as a subject of discussion was the clergy sex abuse scandal that has devastated the American church since 2002. But a private meeting later Wednesday between Benedict and American bishops at the Basilica of the National Shrine of the Immaculate Conception was being closely watched for discussion on the pontiff's trip-opening promise to "do everything possible to heal this wound."
It was only the second White House visit by a pope - the first was 29 years ago - and Bush elected to honor it with a level of pageantry rarely seen even on grounds accustomed to routinely welcoming the world's most important leaders.
Lampposts fluttered with flags in the red-white-and-blue of America and yellow-and-white of the Holy See. The sun-drenched South Lawn was filled to bursting with the largest crowd of Bush's presidency, requiring a large television screen for those in the back. An East Room state dinner was planned for the evening, featuring Bavarian-style food in honor of Benedict's German heritage, even though Benedict himself would be a no-show because of the prayer service with bishops.
Benedict's arrived to a warm welcome from Bush and his wife, Laura. The two leaders strolled along a red carpet to a platform set up on the lawn, and sat stiffly side-by-side as the Marine Band played the national anthem of the Holy See while a 21-gun salute sprayed gray smoke. Famed American soprano Kathleen Battle sang "The Lord's Prayer." The U.S. Army Old Guard Fife and Drum Corps marched by, dressed in colonial garb.
The pontiff had said he was looking forward to meeting a "great people and a great church" during his six-day trip to Washington and New York City. The papal journey coincides not just with Benedict's birthday, but the three-year anniversary of his ascendancy atop the Roman Catholic Church. Nurturing the U.S. flock is a sensitive and important mission for Benedict at a time not just of ongoing scandal in the American church but amid his campaign to tamp down secularism and re-ignite faith.
"I trust that my presence will be a source of renewal and hope for the church in the United States and strengthens the resolve of Catholics to contribute even more responsibly to the life of this nation of which they are proud to be citizens," Benedict said at Bush's side.
The love, both in the audience and outside the White House gates, was evident.
The enthralled South Lawn crowd of more than 13,500 sang "Happy Birthday" - twice, once spontaneously early in the ceremonies with a formal, more full-throated version at the end. A few yelled "Viva il Papa." Four toddlers sat on the grass with handmade signs, one reading "We love you pope of hope" and the other showing a birthday cake - chocolate - with an 81 on it.
In Washington's streets, thousands who were unable to get tickets played music and waved banners as they waited for any glimpse of the pontiff. Benedict didn't disappoint, leaving the White House in his glass-walled Mercedes popemobile for a slow cruise along Pennsylvania Avenue, accompanied by a long motorcade and the pontiff waving from his perch inside.
In brief remarks on the South Lawn, Bush showed off America, ticking off what he said are its best virtues, calling it a nation of prayer and compassion and one that is the most "innovative, creative and dynamic country on Earth" but also among the most religious.
But while acting like the proud custodian of his country, Bush also seemed to suggest that America could use a little tough talking-to by the pontiff.
"In a world where some treat life as something to be debased and discarded, we need your message that all human life is sacred and that each of us is willed, each of us is loved, and each of us is necessary," the president said, drawing sustained applause.
Bush also Americans should see Benedict's U.S. tour as a reminder to "distinguish between simple right and wrong."
"We need your message to reject this dictatorship of relativism and embrace a culture of justice and truth," Bush said. "In a world where some see freedom as simply the right to do as they wish, we need your message that true liberty requires us to live our freedom not just for ourselves."
Adela Arguello, a Department of Homeland Security worker from Miami was touched. "We're living in very terrible times and any message like this is important," she said. "He needed to come."
"How often in life do you get to sing Happy Birthday to the pope?" said Brenda Hawk, a Sunday school teacher from Centreville, Va. "Even if you're not Catholic, it's darn cool!"
Across from the White House, though, the papal visit drew a protest of about 200. With one demonstrator dressed as the pope, the crowd held signs criticizing celibacy and a large banner reading "100,000 sexually abused kids in the US."
The president kicked off the unprecedented series of papal festivities on Tuesday, by motoring to Andrews Air Force Base outside Washington to meet Benedict's plane, something he's never done for any leader. While the pontiff received a rock-star reception on the tarmac, Bush stood back in the unusual role of second fiddle.
