In 1933, Robert J. Mangum arrived in New York as an orphan of 13. As he told the story, he held his little sister by one hand and carried a satchel with all his belongings in the other.
They moved in with an aunt and uncle who lived at the edge of poverty. He sold newspapers, manned a vegetable stand and was a page at the Metropolitan Opera.
Mr. Mangum went on to build a career as diverse as it was accomplished. He became the youngest deputy police commissioner in New York City history, the chief of President Lyndon B. Johnson’s War on Poverty in the Northeast, and the chairman of human rights for New York State.
In 1943, as a 22-year-old police officer, he helped found the Guardians Association, a fraternal group for blacks in the New York City Police Department. It still exists.
In 1963, he joined with David N. Dinkins (who went on to become the first black mayor of New York), Jackie Robinson and business leaders to start One Hundred Black Men, an organization to enhance opportunities and provide role models for minorities. It, too, is still operating, with 116 chapters and more than 10,000 members in the United States and throughout the world. He was the first president of both organizations.
He was also chairman of the New York affiliate of the National Urban League. In 1971, he became the first black judge appointed to the New York State Court of Claims, which adjudicates claims against the state.
Mr. Mangum, who was 93, died on Oct. 2 in the Forest Hill Healthcare Center in Newark. A granddaughter, Sienna Hunter-Cuyjet, confirmed his death.
A congressman appointed him to the United States Military Academy at West Point, but Mr. Mangum turned it down to continue to help his family financially. He was accepted by the Police Department in December 1942 and assigned to walk a beat at a salary of $1,320 a year. After two years, he was promoted to work with youth gangs and juvenile delinquents.
In April 1957, as one of the few blacks in the department, Deputy Commissioner Mangum was sent to Harlem to help deal with public anger over the police clubbing of a Black Muslim. Malcolm X, then a Black Muslim minister in Harlem, was also called to mediate between the police and community members.
In “Resisting Police Violence in Harlem,” a historical pamphlet published in 2012, Mariame Kaba wrote that Mr. Mangum was stung and hurt when Malcolm X, dismissing his efforts, called him a tool of the white power structure.
The one serious blot on Mr. Mangum’s record, and a much-publicized one, came in February 1958, when Police Commissioner Stephen P. Kennedy reprimanded him for “impulsive and improper behavior” after he had gone to a precinct house and drawn a line through the arrest record of a woman he knew. She had been charged with making an improper turn, then causing a ruckus at the precinct.
Although the commissioner emphasized his “outstanding record,” Deputy Commissioner Mangum resigned to manage the political campaign of Earl Brown, a Tammany Hall candidate who was trying to defeat Representative Adam Clayton Powell Jr. of Harlem in the 1958 Democratic primary. Mr. Brown lost.
Mr. Mangum returned to public service in September 1958, when Mayor Wagner named him deputy commissioner of hospitals. Some criticized Mr. Mangum’s lack of experience in the health field. He responded that he had once worked as an office boy for a general practitioner and had excellent management experience.
“Anybody who feels it would take two or three years to familiarize myself with this department really underestimates me,” he said in an interview with The New York Post.
In 1966, Mr. Mangum was appointed director of the Northeast region of the Office of Economic Opportunity, the lead agency in President Johnson’s war on poverty. The New York Times called the position “one of the highest posts” in the antipoverty effort, and said the president had personally approved Mr. Mangum’s appointment.
Gov. Nelson A. Rockefeller named Mr. Mangum chairman of the State Commission on Human Rights in 1967. In that post, he persuaded real estate firms to eliminate racial imbalances in housing, Consolidated Edison to stop discriminating against women on pensions and a gas station to hire a woman. He also forced a minor-league baseball league to hire a female umpire.
In 1971, Governor Rockefeller appointed Mr. Mangum to the claims court, where in 1978 he made the nation’s first ruling on the safety of highway guard rails. He ordered the state to pay $475,000 in damages to an injured driver. He was later general counsel of Beth Israel Hospital in Manhattan.
He is survived by his partner of 30 years, Barbara Baxter Cuyjet; his son, Paul; three stepsons; and besides Ms. Hunter-Cuyjet, three other grandchildren.
As a reminder of his early days, Judge Mangum was said to have kept the satchel he carried when he arrived in Harlem as an orphan.