Coretta Scott King, who died yesterday at 78, was the widow of the civil rights leader Martin Luther King Jr. and a conservatory-trained singer who in the wake of King’s death became one of the most distinctive voices for civil rights, and later for international human rights.

If she never quite assumed King’s charismatic mantle, she nevertheless became the most important guardian of his legacy, leading the campaign for a national holiday in his honor and establishing the Martin Luther King Jr. Center for Nonviolent Social Change in Atlanta.

A passionate yet deliberate matriarch, King raised four children while speaking out on issues of civil rights and poverty. After King was assassinated, she widened his vision to include women’s rights, a theretofore-neglected topic during the civil rights struggle. As black nationalists rose to challenge King’s insistence on peaceful protest, Coretta Scott King was there to assert to the Los Angeles Times in 1969: “You cannot have justice without peace. Peace is the presence of justice in society.”

Most would agree that she failed to develop the King Center effectively, and in recent years it has become a moribund institution as her children wrangled over business matters. It no longer even offers programs on nonviolence, and the King children are split over whether to sell it to the National Park Service. King’s luster, and her own, were undimmed by the family’s attempts to cash in by licensing his words. Yet it added a note of tragic poignance that her later years would be shadowed by such maneuvers, when King had made it his personal byword to avoid any taint of cash.

Most puzzling, perhaps, to supporters was her support of a campaign in recent years to exonerate James Earl Ray, the man convicted of her husband’s murder.

Coretta Scott was raised in rural Heiberger, Ala., where her parents were farmers who were a bit better off than most, living on land the family had owned since the Civil War. Her father made money raising hogs and cattle, and by part-time barbering. He was the first black man in his community to own a truck, and he eventually opened a country store. Like most others, the Scotts were hit hard by the Depression, and young Coretta had the experience of hoeing and picking cotton.

A standout in school and the valedictorian in a high school class of 17, Scott followed her older sister, Edyth, on scholarship to Antioch College in Yellow Springs, Ohio, where Edyth had been the first full-time black student on campus. Scott studied music and education. She seems to have encountered little overt racism until it came time for the student-teaching phase of the program, normally conducted in the Yellow Springs public schools. There had never been a black teacher in the system, and Scott was not to be the first. Attempts to rally support among fellow students, and even from the president of the college, were in vain.

After graduating Antioch in 1951, Scott enrolled at the New England Conservatory to study voice. While in college, she had become a soloist at a local church, and her reputation spread. She received a small scholarship and moved to Boston, where she received room and board in exchange for cleaning the house where she resided with two other students. There was little money for food, and she often lived on crackers, peanut butter, and fruit. Her biographer, Octavia Vivian, wrote in “Coretta: the story of Mrs. Martin Luther King, Jr.” that she “was in the unique position of living at one of the wealthiest addresses in America and starving.” Her situation improved thanks to remittances from her family and a part-time job. She studied with a former star soprano at the Metropolitan Opera, Maria Sundelius.

In 1952, Scott was introduced to King, then a theology doctoral candidate at Boston University, who sized her up as a potential wife in a flash. She seems to have been taken aback by his brash formality: He informed her on the first date that she possessed the four qualities he was searching for in a wife, “character, personality, intelligence, and beauty.” Thrilled by King’s enthusiasm and commitment, Scott eventually abandoned her reservations, not least among them that, as the wife of a clergyman, she would essentially have to abandon her own career. The two were wed at her father’s home on June 15, 1953. The following year, after finishing their educations, they moved to Montgomery, where King accepted the pastorate of the Dexter Avenue Baptist Church. Life was not peaceful for long.

In December 1955, just two weeks after the Kings’ first child, Yolanda (“Yoki”), was born, the Montgomery bus boycott was sparked by Rosa Parks. As King became more involved, his wife handled his growing family, his growing correspondence, and fielded the growing number of death threats made against him. She retained an exemplary composure during two actual assassination attempts again him, a bomb tossed at the family home in 1956, and a knife-wielding woman who injured King enough to hospitalize him in 1958.

King seemed reluctant to allow his wife to step into the limelight he increasingly commanded, but in 1959, as they toured Europe and Asia, she sang before groups in India. She later organized a series of fund-raising “freedom concerts” in which she lectured, sang, and recited poetry about the civil rights movement. She was by his side as he accepted his Nobel Peace Prize, in 1964, as she said, “for something he had not yet achieved. It required him to go back and work harder for it.”

She gained experience serving as delegate to various international conferences, and in 1966, was named in a Gallup poll as one of the most admired women in America.

When she marched at Selma in 1965, it was remarked that it was the first time she had ever appeared in public in flat-heeled shoes.

Both Kings seemed to share a recognition that his ministry was finite. Speaking at a lecture in Seattle in 1965, she said, “You realize that what you are doing is pretty dangerous, but we go on with the faith that what we are doing is right. If something happens to my husband, the cause will continue. It may even be helped.”

In her 1969 memoir, “My Life With Martin Luther King Jr.,” King wrote of another foreshadowing, when he sent her flowers in April 1968, just before leaving for Memphis. “They were beautiful red carnations, but when I touched them, I realized they were artificial. … It seemed so unlike him. I kissed him and thanked him. I said, ‘They are beautiful and they’re artificial.’ ‘Yes,’ Martin said. ‘I wanted to give you something you could always keep.'”

Thus, when King was assassinated in 1968, his widow was prepared both emotionally and by experience to take up far more than the role of designated mourner. Before his body was even in the ground, Coretta Scott King took his place, marching at the head of the garbage workers whose protests had brought her husband to Memphis. Although Martin Luther King Jr.’s assistant, Ralph Abernathy, was named the new head of the Southern Christian Leadership Conference, Coretta Scott King was instantly seen as a second possible inheritor of her husband’s mission.

The sense of competition was heightened after King founded the Martin Luther King Jr. Memorial Center (as it was first called), meaning there were now two rivals for her husband’s legacy, as well as for funds. In 1981, she dedicated an $8.3 million complex that includes a 250-seat auditorium, a 90-seat theater, administrative offices, a library, archives, and the Martin Luther King tomb. She retired as head of the center in 1994, passing the job on to her son Dexter, who passed it on to Martin III in 2004. The center is now moribund and disintegrating, with the bill for estimated repairs standing at more than $11 million.

King led the campaign to create a national holiday to recognize Martin Luther King Jr.’s legacy, solemnized over the objections of a rancorous minority led by Senator Helms, a Republican of North Carolina. It is now celebrated on the third Monday of January.

She was a leader in advocating for international women’s rights, and in 1983 was arrested outside the South African embassy in Washington, D.C., leading a march against Apartheid. She also spoke out against violence in films and television, against gun and toy gun manufacturers, and she called for regulations on advertisements for those products.

In recent years, her activism slowed, but she continued to be an icon of a civil rights movement in need of authentic heroes. Among her many honors were more than 40 honorary doctorates.

As recently as 2004, she spoke out on behalf of the right of same-sex couples to wed.

In a 1972 interview with the Associated Press, she nicely summed up the first half of her life and the remainder as well: “People have to understand I was married to a man I loved, but also to a cause I was committed to – and when the man was no longer there, I still had a cause to which we were both committed which gave me satisfaction and which helps to sustain me.”

Coretta Scott King

Born April 27, 1927, in Heiberger, Ala.; died January 31 at a holistic health center in Rosarito Beach, Mexico, of the effects of a stroke and a heart attack she suffered last August, and cancer; survived by her four children, Yolanda Denise King, Dexter Scott King, Martin Luther King III, and Bernice Albertine King.