Arthur J. Goldberg, 81, an immigrants' son and champion of organized labor who became a Cabinet secretary and associate justice of the U.S. Supreme Court, was found dead yesterday at his home here. His physician, Michael Newman, said Goldberg died of coronary artery disease.

Named to the high court to fill the seat vacated by Felix Frankfurter, Goldberg became a key member of its liberal majority and wrote the landmark 5 to 4 decision in Escobedo v. Illinois holding that confessions cannot be used in court if police question a suspect without letting him consult a lawyer or telling him that his statement might be used against him.

But Goldberg's association with the Supreme Court may be remembered more for the way he left it: accepting the blandishments of President Lyndon B. Johnson who persuaded Goldberg that he could serve his country better as ambassador to the United Nations.

Apparently hoping the U.N. job would lead to his being named secretary of state, Goldberg resigned a lifetime appointment after less than three years on the court, clearing the way for Johnson to nominate longtime friend Abe Fortas.

Both Goldberg's public and private careers were devoted to resolving conflict, but to do this he had to fight. As a union lawyer, he fought crooks and communists, in addition to management. As secretary of labor, he was involved in a titanic and historic struggle with U.S. Steel. Serving at the U.N. during the Vietnam War era, he struggled with U.S. adversaries, his own State Department and, finally, Johnson, over the conduct of the war.

Goldberg came to Washington in 1961 as President John F. Kennedy's first secretary of labor after a distinguished legal career in which he participated in some of the most dramatic moments in union history.

Not only did Goldberg receive unanimous Senate confirmation, but he also was hailed by then-Sen. Barry Goldwater (R-Ariz.) as "the most outstanding choice" in the new Cabinet.

In August 1962, after 1 1/2 years in the Cabinet, Goldberg was nominated by Kennedy to the Supreme Court. When Goldberg left for the United Nations in 1965, following the death of Ambassador Adlai E. Stevenson, Goldberg, who was known for having a healthy ego, he let it be known that he was leaving a lifetime appointment for the less prestigious halls of the United Nations to try to make peace in Southeast Asia.

When Goldberg resigned this post in April 1968, his country was still mired in the Southeast Asian land war and Johnson had been all but driven from office.

Goldberg returned to the private practice of law. He remained in New York, and in 1970, in his only bid for elective office, was the Democratic Party nominee to run against Gov. Nelson A. Rockefeller (R), who won reelection.

Goldberg later returned to Washington, where he practiced law and served on public commissions and as an arbitrator until shortly before his death.

AFL-CIO President Lane Kirkland said yesterday that "few people in history have served the country with greater dedication to the concerns of working men and women and greater devotion to the public interest."

Arthur Joseph Goldberg was born on Chicago's West Side on Aug. 8, 1908, to Joseph and Rebecca Goldberg. His parents were Russian-Jewish immigrants. His father sold produce from a wagon pulled by a blind horse and died when Arthur Goldberg was 8 years old.

By the age of 12, Goldberg was working as a shoe factory delivery boy. He finished high school at the age of 15 and began attending Crane Junior College by day and DePaul University by night. In 1929, he graduated at the head of his class at Northwestern University Law School.

After working as a law clerk and working for a Chicago firm, Goldberg established his own practice. His first labor client was the old American Newspaper Guild, which had struck the Chicago Hearst newspaper. Later in the 1930s, he represented what became the United Steelworkers union and the Chicago and Illinois branches of the Congress of Industrial Organizations (CIO).

Following service in Europe with the Office of Strategic Services during World War II, Goldberg returned to Chicago and became a counsel to the Steelworkers and the CIO. As CIO counsel, he led efforts to oust communists from the union, but insisted on "due process" in accomplishing the goal.

He was a leader in the historic 1955 merger of the CIO with the American Federation of Labor, writing the constitution for the new AFL-CIO.

During the 1950s, Goldberg cooperated with congressional committees investigating corruption in organized labor and became friends with a young Senate committee counsel, Robert F. Kennedy.

"Three days after I came to Washington in 1953 as assistant attorney general, I argued a case against Arthur Goldberg in the 2nd Circuit," retired chief justice of the United States Warren E. Burger recalled yesterday, "and we have been warm friends since then. He was an outstanding lawyer and spokesman for organized labor and as a justice of the Supreme Court he was a balanced and thoughtful jurist."

In 1958, Goldberg backed labor reform legislation proposed by Robert Kennedy's brother, Sen. John F. Kennedy (D-Mass.). Goldberg led organized labor groups backing Kennedy's 1960 presidential campaign.

Goldberg's labor career was summed up by a former law clerk, Georgetown University Prof. Peter Edelman who said, "He really helped the labor movement grow into a mature institutional force in this country. When he began in the 1930s, it was still fighting the basic struggles for recognition."

As secretary of labor, Goldberg was instrumental in persuading United Steelworkers President David J. MacDonald to agree to only modest wage gains in the union's 1962 deliberations with giant U.S. Steel.

It was felt that large increases in wages and prices in the steel industry would disrupt the economy and endanger a period of recovery that was underway.

After the union held the line, the steel company unexpectedly announced a price increase. Goldberg was a vocal proponent of possible measures to be taken against the company. U.S. Steel quickly backed backed down and announced there would be no price increase.

Goldberg used his office not only to help mediate large and knotty labor disputes, but he also announced that the government should assert the "public interest" in disputes. On occasion, he intervened directly to recommend settlements.

His hand was seen not only in contract settlements involving the steel industry but also in disputes ranging from dockworkers to symphonies.

Goldberg also spoke out for increased job training and against racial discrimination in the workplace. He headed a drive to recruit black college graduates for government work.

His arrival at the Supreme Court, some observers said, marked the real beginning of the "Warren Court." With the addition of Goldberg, the liberal wing of the court, led by then-Chief Justice Earl Warren, had five solid votes for the first time. Edelman, his former clerk, recalled Goldberg as an intellectual leader of the court and someone skilled at weaving together a majority.

Beside his majority opinion in the Escobedo case, Goldberg played a major role in the decisions on civil liberties and civil rights that were the hallmark of the Warren era.

Goldberg was said to have been particularly proud of the majority opinion he wrote in Watson v. Memphis signaling that the court was sick of foot-dragging on civil rights, and that "all deliberate speed" had come to mean "now" to a majority of the justices.

He also wrote a concurring opinion in Griswold v. Connecticut, a landmark privacy ruling that served to strike down many state laws involving sexual practices as unconstitutional. The laws were judged a violation of the Ninth Amendment and a person's right to privacy.

Goldberg also wrote dissents in capital punishment cases, saying that the death sentence was unconstitutional and holding that it was "cruel and unusual punishment."

His departure from the court stunned the political world. Although whatever hopes he may have had for succeeding Dean Rusk as secretary of state were never fulfilled, Goldberg did not find his service at the United Nations dull. During his ambassadorship, the United Nations tried to arrange cease-fires between India and Pakistan in 1965 and in the Middle East in 1967. Goldberg demonstrated what some historians have seen as dexterous footwork in working with Soviet Ambassador Anatoliy Dobrynin in arriving at a realistic resolution on a permanent Arab-Israeli settlement. It called for recognition of Israel by the Arab states and Israel's pulling back to its pre-1967 borders.

But historians of the period also record that Goldberg was unable to accomplish anything with regard to Vietnam and became another of its casualties. By the end of his tour, President Johnson was enraged by Goldberg's constant calls to the White House and State Department for deescalation of the war in Vietnam.

His 1970 bid for the New York governorship was generally considered a political disaster. While Rockefeller reveled in pressing the flesh and delighted in being called "Rocky," Goldberg told aides to be sure to address him as "Mr. Justice."

His wife of 57 years, the former Dorothy Kurgans, died in 1988. Survivors include a son, Robert, of Anchorage and a daughter, Barbara Goldberg Cramer of Chicago.