The widow of American civil rights legend, Martin Luther King Junior, has died in her sleep at the age of 78, her family announced on Tuesday.
"Her daughter went in to wake her up and she was not able to and so she quietly slipped away. Her spirit will remain with us just as her husband's has," Andrew Young, a family friend and former civil rights activist said.
Ms Scott King died at 0700 GMT of a heart attack at a holistic clinic in Rosarito, Mexico, said institution director Humberto Simanti.
She had also been fighting ovarian cancer and last year suffered a heart attack and stroke.
Her body was being taken to Atlanta, Georgia for burial.
Highlights of this peaceful woman's life......
Born April 27, 1927 in segregated Alabama, Ms Scott King grew up on her parents' farm.
Her father, Obediah Scott, was the first black man in the area to own a truck and then launched a truck-farming business, which drew opposition from white neighbours.
Her mother, Bernice, frustrated that buses took only white children to school, rented a bus to transport black children to classes.
In 1945, after graduating from high school, Ms Scott King followed her older sister to College, where she earned a degree in music and elementary education.
Her sister was the college's first full-time black student.
Ms Scott King went on to study at the New England Conservatory of Music in 1951, where she met her future husband.
The promising singer married Martin Luther King Jr in 1953 immediately supporting his equal rights campaign, often speaking in the Nobel Peace prize laureate's place when he was unable to attend an engagement.
She was with him in 1963 when he delivered his famous "I Have a Dream" speech at the Lincoln Memorial in Washington.
Four days after his assassination in 1968, Ms Scott King led an equal rights march by 50,000 people through the streets of the Tennessee city.
In the following years, while raising four children, she campaigned fiercely to keep alive her husband's husband's message of non-violent change.