Reagan died Sunday morning in her home in Los Angeles, said Joanna Drake in a statement on the Ronald Reagan Presidential Library’s website.
Reagan was born Anne Frances Robbins on July 6, 1921, in New York City to Edith Luckett, an actress, and Kenneth Robbins, a car dealer who left the family soon after she was born.
In 1929, her mother married Loyal Davis, a neurosurgeon, and the family moved to Chicago.
Davis formally adopted her in 1935 and her name was legally changed to Nancy Davis.
She attended Smith College in Massachusetts, graduating in 1943.
She subsequently went into acting, working in film, television, and stage productions.
She met Ronald Reagan, the actor who would eventually become the 40th president of the United States, and they married in 1952.
Mrs Reagan, who died of congestive heart failure in Los Angeles on Sunday, was also praised by other senior US politicians and foreign leaders.
Her 52-year marriage to Ronald Reagan was once described as the US presidency’s greatest love affair.
In a statement, the Obama family said:
“Nancy Reagan once wrote that nothing could prepare you for living in the White House.”
She was right, of course.
“But we had a head start, because we were fortunate to benefit from her proud example, and her warm and generous advice.
Our former first lady redefined the role in her time here.”
Obama and his wife Michelle said they were
“fortunate to benefit” from Mrs Reagan’s “proud example”.
As first lady, she sought to emulate the style of one of her predecessors, Jackie Kennedy.
Like her husband, Mrs Reagan was a former Hollywood performer who made it all the way to the White House.
As Nancy Davis, she was an actress during the 1940s and 1950s and married Mr Reagan, a prominent film actor, in 1952.
After her husband died of Alzheimer’s in 2004, she became a champion for Alzheimer’s patients, raising millions of dollars for research and breaking with fellow conservative Republicans to argue for stem cell studies.
Mrs Reagan’s best-known project as first lady was the anti-drugs “Just Say No” campaign.
“There are people who told me it gets much easier,”
Reagan said in 2007 about grieving the loss of her husband.
“Well, maybe for them, but not for me. I miss him more now than I ever did.”
Mrs Reagan will be buried next to her husband, at the Ronald Reagan Presidential Library in Simi Valley, California, the library said in a statement.
Meanwhile, former President Bill Clinton and former Secretary of State Hillary Clinton, who is a Democratic presidential hopeful, said:
“Nancy was an extraordinary woman: a gracious first lady, proud mother and devoted wife to President Reagan – her Ronnie.”
Israeli Prime Minister Benjamin Netanyahu said:
“I remember Nancy as a noble woman who supported President Reagan and stood by his side.
She will be remembered as a great friend of the state of Israel.”
Former Republican presidential candidate Mitt Romney tweeted that
“with the passing of Nancy Reagan, God and Ronnie have finally welcomed a choice soul home”.
Former President George W Bush said:
“Mrs Reagan was fiercely loyal to her beloved husband and that devotion was matched only by her devotion to our country.
Her influence on the White House was complete and lasting.”
Reagan is survived by her son Ron Reagan and daughter Patti Davis, who runs support groups for family members of people with Alzheimer’s.