Coretta Scott King had been in failing health since suffering a stroke and a heart attack in August.
"She managed a graceful and beautiful passing," said the Rev. Andrew Young, the former ambassador to the United Nations.
Still, when the news of her death arrived, it was a blow to the millions of Americans who had come to regard her as an icon of the civil rights movement. Coretta Scott King had become the embodiment of her late husband's message and made his legacy her own.
"I just want to do God's will," said Martin Luther King Jr. on April 3, 1968, the night before he was assassinated.
"You can rest assured that I'm going to keep active in the non-violent movement to fulfill the dream," said Coretta on her husband's birthday in 1995.
It was not the life she'd envisioned — wife and widow of a civil rights crusader. But it was a struggle she knew well.
"Long before she met Martin Luther King Jr., long before she married the man, she was working for peace," says Rep. John Lewis, D-Ga.
She was born Coretta Scott in 1927 in a tiny two-room home in Alabama. Her childhood, like those of all African-Americans at the time, was defined by race.
"She came from a very strong family, strong women in that family," says the Rev. John Lowery, the co-founder of the Southern Leadership Council. "Only a strong man would choose a bride like Coretta, who was in her own right a full, complete person."
When she met her future husband, Coretta was studying music in Boston. Charmed by her grace and confidence, King said he was determined to win her over. They married two years later. It would not be an easy life.
"I remember the night that Dr. King was killed," says the Rev. Jesse Jackson. "I called her by their bedside phone, a very difficult phone call to make, and I didn't quite know how to put it except to say, 'Mrs. King, he has been shot.' Intuitively, she really knew what had happened."Slideshow: Coretta Scott King
Though her husband's death shattered her life and a nation, there was no time to mourn. Just four days after his death, Coretta Scott King led 50,000 people on a march in Memphis.
But even with the significant contributions she made to this country, she was proudest of the legacy she and her husband achieved together — their children.
"I am going to keep on marching for justice, equality, peace and reconciliation of the human family until I am called home, said Coretta in 1995.
Mrs. King died at an alternative medicine clinic in Mexico. In a statement Tuesday night, her family says she had ovarian cancer, and that doctors in this country considered her terminal. She was in Mexico to consider possible alternative treatment.
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