Truman K. Gibson Jr., a Chicago attorney who had been the last surviving member of the World War II-era "black Cabinet" of Presidents Franklin D. Roosevelt and Harry S Truman, died Friday at Mercy Hospital after an illness of five weeks. He was 93.

As an advocate for African- American soldiers in the War Department from 1940 through 1945, Mr. Gibson fought tirelessly to break down the segregation that ruled the U.S. Army, to persuade the military leadership to commit black servicemen to combat instead of relegating them to service and support duty, and to protect the rights and even the lives of African-American soldiers trained at camps mostly in the Jim Crow South where white violence was a constant threat.

"Truman Gibson was one of the great resources of the civil rights battles who was never acknowledged as he should have been," said Abner Mikva, the former Illinois congressman, federal appellate judge and White House counsel.

That story was the heart of Mr. Gibson's memoir, Knocking Down Barriers: My Fight for Black America, published this year by Northwestern University Press.

"I am just so thankful that he got to do that book, to say what he wanted to say," said his daughter, Karen Kelley of New York. "He lived nearly 94 years pretty much on his own terms, and it was such a wonderful life."

Born in Atlanta on Jan. 22, 1912, Mr. Gibson moved with his family to Chicago in 1929. His was a life that touched on many of the critical issues of race in America in the 20th century.

As a young graduate of the University of Chicago Law School, Mr. Gibson was a member of the legal team that challenged a restrictive racial covenant prohibiting African Americans from living in the Washington Park area of the South Side. He spent months poring over property deeds to build the factual basis for the U.S. Supreme Court case that overturned the covenant. The plaintiff was black real-estate developer Carl Hansberry, whose daughter Lorraine would use the experience as inspiration for her 1959 Pulitzer Prize-winning play "A Raisin in the Sun."

In 1940, Mr. Gibson served as executive director of the American Negro Exposition, which was in effect a black world's fair to commemorate the 75th anniversary of emancipation, showcase black excellence in the arts and entertainment, and celebrate African-American contributions to U.S. history. The two-month-long expo in Chicago featured Duke Ellington, Paul Robeson, Lionel Hampton, Count Basie and other famous entertainers of the day.

With the outbreak of war in Europe and the increasing likelihood that the United States would be drawn in, the Roosevelt administration sought to answer the growing outcry from black Americans over the segregated military and the second-class support status of African Americans in the military. Already black leaders such as Mary McLeod Bethune served in New Deal agencies, constituting a "black Cabinet," so the administration created the office of civilian aide to the secretary of war as an advocate for African Americans. Mr. Gibson served as an assistant to the first civilian aide, William Hastie, and in 1943 was promoted to the job after Hastie quit.

It was an often-thankless challenge, with the generals bristling at any suggestion of change from Gibson, and civil rights leaders complaining about lack of progress. The Army insisted that it couldn't get ahead of civilian society in race relations.

" 'The Army is not a sociological laboratory" . . . was the sorry rationale for segregation that I was to hear General George C. Marshall, the army's chief of staff, and other commanders repeat ad nauseam," Mr. Gibson wrote in his memoir.

Backed by a few white officials in the War Department and some increasingly vocal white northern politicians as well as natural allies such as Roy Wilkins and Walter White of the NAACP and a strident black press, Mr. Gibson played an influential role in finally convincing the Army that it had to commit African-American troops to battle. Most notably, the black 92nd Infantry Division was thrown against the heavily fortified German Gothic Line in northern Italy in early 1945 in a terrible bloodletting that remains a source of controversy.

In the 1940s, civil rights advances often were measured in small steps as opposed to the major strides of the 1950s and '60s. It's hard for 21st century sensibilities to comprehend the huge effort required by Mr. Gibson just to get the Army to tell unit commanders they were responsible for maintaining smooth race relations and to goad the War Department into asking, usually unsuccessfully, for federal prosecution of whites in the South, often law enforcement officers, who assaulted and murdered African Americans called to the service of their country.

Mr. Gibson was an adviser to filmmaker Frank Capra of "It's a Wonderful Life" fame in making the movie short "The Negro Soldier" to demonstrate to the civilian population the African-American contribution to the war. He got Joe Louis, the world heavyweight boxing champion, to form a group of boxing champs to put on matches at Army bases here and aboard.

Morris J. MacGregor Jr., a historian of the military's relationship with African Americans, wrote in his Integration of the Armed Forces, 1940-1965, "Dedicated to the abolition of racial segregation, Gibson eschewed the grand gesture and emphasized those practical changes that could be effected one step at a time." As a result, MacGregor wrote, "the Army for the first time began to agree to practical if not policy changes."

After the war, President Truman appointed Mr. Gibson, whom he called "my namesake," to the Advisory Commission on Universal Military Training, which he used as a platform to campaign against segregation, in testimony before Congress. In one White House meeting, the president told Mr. Gibson that he intended to end the practice, and the Chicagoan provided input into the planning of the 1948 executive order to end military segregation.

Mikva praised Gibson's role in helping persuade President Truman to integrate the armed forces and called Truman's order "the most important thing the government had done since the 13th, 14th and 15th amendments to the Constitution."

Mr. Gibson had met boxing champ Louis and become his lawyer in the 1930s. During the war, Louis often reported to Mr. Gibson about racial conditions on Army posts, enlisting him in helping future baseball great Jackie Robinson avoid a court-martial for striking a racist officer. After the war, his association with Louis propelled Mr. Gibson into a career as one of the nation's premier boxing promoters.

With Chicagoans James Norris and Arthur Wirtz, he ran the International Boxing Club, which ruled the sport until declared a monopoly by the courts in 1959. Mr. Gibson pioneered network television broadcasting of the sport -- the New York Times called him "a profound advocate of television's marriage to boxing" -- but he had to spend much time fending off accusations of mob influence in boxing. The government prosecuted him over allegations about the management of a minor fighter, one of several legal problems in Mr. Gibson's later years.

After leaving boxing, Mr. Gibson returned to law practice in Chicago. Wanemond Smith, his law partner for the last decade, said, "He taught me so much, not just about the law but about life and how to deal with people."

Mr. Gibson practiced law until his health failed after he suffered a stroke and heart attack Nov. 17. Besides his daughter, survivors include two grandchildren, three great-grandchildren and one great-great-grandchild.