The cause of death was complications from heart disease.
Mr. Maxwell, 87, known for several years as Dan Rooney on TV's "General Hospital," was a longtime union activist and past president of the American Federation of Television and Radio Artists, former first vice president of Actors' Equity, board member of the Screen Actors Guild and trustee of the AFTRA Health and Retirement Fund.
During his long career in Hollywood, Mr. Maxwell appeared in scores of motion pictures including "Lonelyhearts," "By Love Possessed," "Rage to Live," "The Intruder" and "Madame X"; plus four television series and many roles on other programs.
Born in New York City, Mr. Maxwell made his Broadway debut shortly after graduating from the University of Michigan with a bachelor of arts degree.
During World War II, he was a B-29 bombardier-navigator with the U.S. Air Force and held the rank of First Lieutenant. After the war, he returned to Broadway where he also appeared in At War With the Army and Death of a Salesman. He also appeared in the London production of Death of a Salesman, according to AFTRA.
Mr. Maxwell was an active member of the American Federation of Television and Radio Artists, serving as national president of the 80,000-member union of actors, broadcasters and recording artists for five consecutive terms, from 1984-89. He also served as president of the union's Los Angeles Local for five years, and from 1985 until his death he was a trustee of the AFTRA Health & Retirement Funds and a member of AFTRA's board of directors.
In addition to his longtime affiliation with AFTRA (he held membership card No. 39, issued in 1937), he also served on the National Board of its predecessor organization, Television Authority.
An AFTRA announcement indicated Mr. Maxwell began his performing career as a dancer at the 1939 World's Fair. He later "worked every nook and cranny of our wretched and glorious business with verve and nerve."
AFTRA national president John Connolly said, "Frank fought facism in the belly of a B-29 in World War II, McCarthyite blacklisting at the peril of his television career in the 1950s, and racism on the front lines of the civil rights struggle in the 1960s... He brought dignity, self respect and a sense of empowerment to the 80,000 members of AFTRA."
Mr. Maxwell is survived by a daughter, Chris Maxwell, of Los Angeles.