Judge Constance Baker Motley, 84, the first African American woman appointed to the federal judiciary and the only woman on the NAACP legal team that won the epochal school desegregation decision Brown v. Board of Education, died Sept. 21 of congestive heart failure at New York University Downtown Hospital. At the time of her death, she was senior judge for the U.S. District Court for the Southern District of New York.

Long before she ascended to the federal bench, she was a key figure in many of the major legal battles of the civil rights era. She represented Martin Luther King Jr., Ralph Abernathy and other civil rights leaders when they were locked up in fetid Southern jail cells. She stayed in Medgar Evers's home not long before an assassin killed him in his front yard, and she was on the podium at the Lincoln Memorial in 1963 when King delivered his "I Have a Dream" speech.

As a young lawyer with the NAACP Legal Defense and Education Fund, she helped Thurgood Marshall, then chief counsel of the fund, write the legal brief for the Brown case and then listened as he delivered his argument before the Supreme Court.

She and her colleagues did not anticipate the unanimous decision, she recalled. "We thought we might come out with five to four, but when it was unanimous, we were flabbergasted," she said in a 2003 interview with an American Bar Association magazine. "In fact, we thought we might even lose. . . . [Chief Justice] Earl Warren did that. He understood, having been a politician, that you had to have unanimity, because if you had a divided court, the Southerners would still be at it. . . . What we did not anticipate was the massive resistance to Brown in the South."

After the 1954 ruling, she threw herself into what she called "the second civil war." Writing hundreds of court papers and legal briefs to enforce Brown, she argued 10 school desegregation cases before the U.S. Supreme Court, winning nine of them.

In 1956, she represented Autherine Lucy, the daughter of a black tenant farmer who had applied to graduate school at the University of Alabama.

In 1961, she represented Charlayne Hunter (now Hunter-Gault) and Hamilton Holmes in their effort to enter the University of Georgia.

In 1962, she represented James H. Meredith in his arduous but ultimately successful battle to gain admission to the University of Mississippi. Marshall gave her the case, she said, because she was a woman. "Thurgood's theory was, in the South, they don't bother black women because they all have mammies," she once said.

Meredith was admitted after 16 months of legal wrangling, numerous court hearings and tortuous legal resistance on the part of Mississippi officials, including Gov. Ross Barnett, who eventually was held in contempt of court.

"She was indomitable," said Jack Greenberg, who succeeded Marshall as director-counsel of the NAACP Legal and Education Fund and is now a professor at Columbia University School of Law. "She would take on a project like opening up the University of Mississippi and just keep coming back again and again and again. She was like Grant at Vicksburg. She just dug in there and stayed there until they rolled over."

In 1963, she represented more than 1,000 black children in Birmingham who had been suspended from school for participating in civil rights demonstrations. The same year, she led the NAACP's successful effort to prevent Gov. George C. Wallace from blocking school desegregation in four Alabama counties.

Both in the courtroom and on the bench, she impressed those who knew her with what Greenberg called her presence. "That Motley woman," as her Southern antagonists often referred to her, was tall and always elegantly dressed. Always well prepared, deeply versed in the intricacies of the law, she was soft-spoken and reserved, Greenberg recalled, but formidable.

Her successor, Chief Judge Michael B. Mukasey, recalled appearing in her courtroom as an assistant U.S. attorney in the 1970s. "She was very calm," he said. "She was the kind of person who could control a courtroom because everyone knew who she was."

Constance Baker was born in New Haven, Conn., on Sept. 14, 1921, the ninth of 12 children born to parents who had migrated earlier in the century from the island of Nevis in the West Indies. Her father was a cook for Skull & Bones, one of Yale University's elite social clubs.

Attending New Haven's integrated public schools, she became a voracious reader at an early age. She learned about W.E.B. Du Bois and other black heroes from lectures she heard at the Episcopal church. Reading a book about Abraham Lincoln that she had checked out of the New Haven Public Library, she decided at age 15 that she wanted to be a lawyer. She was impressed by Lincoln's observation that the legal profession was the most difficult.

Her mother wanted her to be a hairdresser. "She had no conception of a woman wanting to be a lawyer," Judge Motley told the ABA magazine.

After graduating with honors from New Haven High School, she worked briefly as a maid before accepting a job with the New Haven branch of the National Youth Administration. She happened to give a speech one night at the Dixwell Community House, an African American social organization, urging that black members be given greater control over the facility. In the audience was Clarence Blakeslee, a wealthy white contractor and philanthropist who had built the community house. The grandson of Abolitionists, he was impressed with her energy, poise and eloquence and offered to pay for her education.

She enrolled at Fisk University in Nashville. On the train headed south, she experienced for the first time the reality of segregation when she was directed to ride in the Jim Crow car. On her first trip home, she brought her parents a souvenir of Southern life, a sign that read "Colored Only."

She stayed at Fisk for a year and then transferred in 1942 to New York University, where she received a bachelor's degree in economics.

In 1944, she became one of the first black women accepted at Columbia University Law School. During her first year, she met Marshall, who offered her a job as law clerk at the NAACP Legal Defense Fund office in New York. She received her law degree in 1946 and became a full-fledged member of the staff. Her early work focused on housing discrimination.

After passing the New York bar examination in 1948, she became assistant counsel of the Legal Defense Fund. She got her first courtroom experience in 1949 as Marshall's assistant on a Jackson, Miss., equal-pay case that an African American teacher had brought against the Jackson public school system.

"Woman lawyers were a joke in most courthouses and unheard of in virtually every place except New York City," Judge Motley wrote in Ms. magazine years later. "The whole town turned out to see the Negro lawyers from New York, one of whom [was] a woman."

For the next 15 years, she served as a key attorney on dozens of school desegregation cases in 11 Southern states and the District. It was the best job she ever had, she recalled in the ABA interview. "Plus, we were like a family," she said. "I tried a lot of cases before I came on the bench, which is probably more exciting. But, you see, I coincided with history as I see it now."

After leaving the Legal Defense Fund in 1964, she became the first black woman elected to the New York State Senate. The next year, she was selected to fill the vacant post of Manhattan borough president and then was elected nine months later. Again, she was the first black woman to hold the office.

In January 1966, President Lyndon B. Johnson named her to the District Court for the Southern District of New York, a region that includes Manhattan, the Bronx and six counties north of the city. The first African American woman to serve as a federal judge, she became chief judge in 1982. She took senior status, handling a reduced caseload, in 1986.

Several of her rulings stand out, including the 1978 case that allowed female reporters to enter the locker rooms of professional sports teams. In 1987, she ruled that, without exceptional circumstances, suspects cannot be detained more than 24 hours without a court ruling that sufficient evidence exists to justify the arrest.

In addition to numerous articles and essays, she was the author of "Equal Justice Under Law: The Life of a Pioneer for Black Civil Rights and Women's Rights" (1988). She was inducted into the National Women's Hall of Fame in 1993.

Survivors include her husband of 59 years, Joel Wilson Motley Jr. of New York; a son, Joel Wilson Motley III of Westchester County, N.Y.; three sisters; a brother; and three grandchildren.

Judge Constance Motley stands in her chambers at federal court in New York, where she was on senior status.President Lyndon B. Johnson names Motley to a federal judgeship, a first for a black woman, in 1966. She had been Manhattan borough president.