An unusual bipartisan spirit was on display at the service at the Washington National Cathedral with both Republican and Democratic politicians gathering to honor a president who called for a "kinder, gentler" nation.
Bush, the 41st U.S. president, died last week in Texas aged 94.
"You'll see a lot of joy," said Ron Kaufman, Bush's White House political director in his unsuccessful re-election campaign in 1992. "It'll show the way of life that people took for granted in many ways and now kind of long for."
Hundreds of people lined Pennsylvania Avenue in downtown Washington to watch a hearse drive Bush's coffin from Capitol Hill, where he had lain in state since Monday night, toward the cathedral. Bush was president from 1989 to 1993.
Political feuds were briefly set aside in honor of the late president, a naval aviator who was shot down over the Pacific Ocean in World War Two, and a commander in chief who defeated Iraqi forces in the 1991 Gulf War.
Trump shook hands with his predecessor, former President Barack Obama, who he has often sharply criticized, as he took his seat at the cathedral.
Democratic former Secretary of State Hillary Clinton, Trump's 2016 election opponent, and her husband Bill Clinton shared the front pew with Obama, Trump and their spouses.
Bush has been remembered as a patrician figure who represented a bygone era of civility in American politics.
He was voted out of office in 1992 in part for failing to connect with ordinary Americans during an economic recession. But his reputation for moderation and politeness has shone more brightly in recent years in light of the divisiveness and anger in the United States that accompanied the rise of Trump.
TRUMP AT SERVICE
"Looking forward to being with the Bush family. This is not a funeral, this is a day of celebration for a great man who has led a long and distinguished life. He will be missed!" Trump tweeted on Wednesday.
The Trumps spent about 20 minutes visiting with the Bush family on Tuesday.
All surviving former U.S. presidents were at the cathedral along with their wives.
George W. Bush was to deliver a eulogy, along with former Canadian Prime Minister Brian Mulroney, retired Wyoming Republican Senator Alan Simpson and presidential biographer and former journalist Jon Meacham.
The guest list included Britain's Prince Charles and leaders of Germany, Jordan, Australia and Poland, along with a host of former world leaders, such as former British Prime Minister John Major, who was in office during Bush's term.
Marlin Fitzwater, who was the late president's White House press secretary, said the ceremony "will show a quality of gentility and kindness that he was noted for."
Trump closed the federal government on Wednesday to mark a day of mourning for Bush, and several U.S. financial exchanges were closed.
Bush, who had been President Ronald Reagan's vice president, navigated the United States through the end of the Cold War and was president when the Berlin Wall fell in 1989.
He was dogged by domestic problems, including a sluggish economy, and faced criticism for not doing enough to stem the tens of thousands of deaths from the AIDS virus ravaging America.
When he ran for re-election in 1992, he was pilloried by Democrats and many Republicans for violating his famous 1988 campaign promise: "Read my lips, no new taxes." Democrat Bill Clinton coasted to victory.
Thousands of people filed past Bush's body to pay their respects when it lay in the Capitol Rotunda, some getting a chance to see Sully, a service dog who was Bush's friendly companion. Sully became an internet sensation after being photographed lying next to his late master's coffin.
(Additional reporting by Richard Cowan, Susan Heavey and Jeff Mason Writing by Steve Holland and Alistair Bell Editing by Lisa Shumaker and Frances Kerry)
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)