The body of former US leader Ronald Reagan is lying in state at his presidential library in California at the start of five days of mourning.
Mrs Reagan briefly lay her head on the coffin
Thousands have been queuing to pay respects at the closed casket before it is taken to Washington late on Tuesday.
His widow Nancy oversaw the arrival of the flag-draped coffin, carried inside by an honour guard while a band played.
Reagan died in Los Angeles on Saturday at the age of 93, after a 10-year battle with Alzheimer's disease.
Once the coffin had been placed on a plinth in the lobby of the presidential library, there was a brief prayer ceremony led by Reagan's former parish priest, the Reverend Michael Wenning.
1911: Born in Tampico, Illinois
1937: Wins Hollywood contract
1966-74: Serves as governor of California
1981-89: Serves as 40th president of the US
Mar 1981: Survives an assassination attempt
1994: Reveals he has Alzheimer's Disease
Throughout the service Mrs Reagan clutched the hand of her tearful daughter Patti Davis, then as it concluded, briefly lay her head upon her husband's casket.
Earlier, in her first public appearance since her husband's death, Mrs Reagan had joined her children in the gardens at the Santa Monica mortuary where he had lain, examining the many floral tributes and goodwill messages.
Some well-wishers had left packets of jelly beans, the former leader's favourite sweets.
When Reagan's body was carried from the small mortuary to make the journey to his Simi Valley library there was applause for both him and his wife from gathered onlookers and salutes from attending police officers.
Along the route people crowded walkways and bridges to catch a glimpse of the passing hearse.
The BBC's Michael Buchanan in Simi Valley says the public have already been turning up in sizeable numbers to say farewell. They are being ferried up to the hilltop library by bus.
All along the route crowds gathered to watch the motorcade
Among the first in line were California Governor Arnold Schwarzenegger and his wife Maria Shriver. Mr Schwarzenegger said Reagan had been a "hero".
"He was a great American patriot. I did not just admire him, I was fortunate enough to know him. He was a hero to me," he said.
Reagan's body will lie in state at the presidential library until Wednesday, then it will be flown to Washington to lie in state in the US Capitol.
The coffin will be carried on a gun carriage to the US Capitol.
Reagan will be the first president to lie in state since Lyndon B Johnson in 1973.
The only other president to die in the interim was Richard Nixon, who left office disgraced by the Watergate scandal.
The mourning period will culminate in a full state funeral at the National Cathedral on Friday, which many world leaders are expected to attend.
Reagan's body will then be flown back to California for a private sunset burial at the presidential library.
As the detailed plans were announced, the Reagan family issued a statement,
saying they were "deeply touched by the outpouring of sympathy from across the
country and around the world".
Reagan lived longer than any US president
Tributes have continued to pour in for the former president.
Ex-Soviet leader Mikhail Gorbachev said Reagan was a "great president" who was "instrumental in bringing about the end of the Cold War".
French President Jacques Chirac called him a "great statesman".
"He made you feel safe and secure regardless of whether you voted for him or not," one man, John Circenis told Reuters news agency.
In November 1994, five years after leaving office, Reagan revealed that he was suffering from Alzheimer's disease, which destroys brain cells and causes memory loss.
He died with his wife of 52 years, Nancy, and the couple's children Ron Reagan and Patti Davis at his bedside.
Mrs Reagan wrote in a Time magazine article released on Sunday that her husband was an "eternal optimist" who always prayed silently while travelling by aeroplane.
"I think his faith and comfort with himself accounts for that optimism," the former first lady wrote.
"Since he felt that everything happens for a reason, he never saw things darkly."
Reagan was the 40th president of the US, taking office at the age of 69, the oldest to do so. He lived longer than any US president.
Before entering politics he appeared in more than 50 Hollywood films. He described himself as the Errol Flynn of B-movies.