The cause was a heart attack, said Anthony L. Geist, Mr. Osheroffs friend and chairman of Spanish and Portuguese studies at the University of Washington.

Mr. Osheroff wove his most enduring legacy from the threads of his life. It was a 1974 film, "Dreams and Nightmares," which told of his journey from the streets of Brooklyn to the Spanish battlefields of the 1930s to a melancholy return to Spain a generation later.

He used the movie, which won several prizes in Europe, as an entree to teaching jobs at the University of California, Los Angeles, and the University of Washington, and to countless speaking engagements at colleges, high schools and other forums across the nation. He continued to work as a union carpenter.

Mr. Osheroffs last speech was in San Francisco on March 30, when he spoke from a wheelchair at the unveiling of a monument to the 3,000 American volunteers to fight Franco in what came to be called the Abraham Lincoln Brigade. Nine hundred were killed.

"The stuff were made of never goes away, with or without monuments," he said in the old-time Brooklyn accent he never lost, Mr. Geist and other friends said. "Because the bastards will never cease their evil, and the decent human beings will never stop their struggle."

Eleven of the 39 surviving Lincoln Brigade veterans attended the speech. On April 7, two more died: Abe Smorodin, 92, of Brooklyn, and Ted Veltfort, 92, of Oakland, Calif. Three dozen remain.

Mr. Osheroff achieved a higher profile among generations of leftists, not least because of his gift of gab. His political involvement began at 12, when he joined the broad protest against the conviction of the anarchists Sacco and Vanzetti.

Soon, he was arrested for helping evicted tenants immediately move their belongings back into their apartments. He organized coal miners and steelworkers and once ran for the New York Legislature as a Communist.

Going to Spain in May 1937, he swam the final two miles to shore after his ship was sunk. He fought in four battles before machine-gun fire shattered a knee, and he returned home in August 1938.

He even managed the obligatory fistfight with Hemingway, in his case over food he admitted he was stealing from the writer.

When Mr. Osheroff arrived in Mississippi in 1964 to build a community center during the Freedom Summer of 1964, his car was blown up the night he arrived. He aided the leftist government in Nicaragua by organizing a team of Americans to build houses for a peasant cooperative.

In 2006, he was still prowling Seattle in a van, criticizing the Iraq war over a loudspeaker. The same year, he was arrested for the last time at a sit-in protest.

"My ship is slowly sinking, but my cannons keep firing," Mr. Osheroff said in a 2005 interview with Robert Jensen, a University of Texas journalism professor. "Or, heres another way to say it: I have one foot in the grave and the other keeps dancing."

Abraham Osheroff was born in the Brownsville section of Brooklyn in October 1915. His mother, a seamstress in a sweatshop, and father, a carpenter, were Jews who emigrated from Russia. His first language was Yiddish, his second, Russian, and his third, English. He told of being so rebellious that he tried to burn down Erasmus Hall High School.

He graduated from the City College of New York, then organized industrial workers in Pennsylvania, winning respect with arm-wrestling skill. He went to Spain after seeing newsreels of Nazi planes bombing the undefended city of Guernica.

His losing run for the Legislature came in 1940, and the next year he joined the Army, in which he helped in mop-up operations after D-Day. After the war, he moved frequently, to avoid federal investigators hunting Communists. He worked on a dude ranch and for a company that wrote term papers for college students, among many other jobs.

Mr. Osheroff became disillusioned with the Communist Party in 1956, and left it. His later political involvements included fierce opposition to the Vietnam War and fighting real estate developers in the Venice section of Los Angeles.

In 2000, Mr. Osheroff made another movie, a documentary about posters from the Spanish Civil War.

Mr. Osheroff was married three times. He is survived by his companion, Gunnel Clark; his daughter, Sarah, of Portland, Ore.; and his sons Dov, of Berkeley, Calif., and Nick, of Los Angeles.

Like many other Lincoln Brigade veterans, Mr. Osheroff believed World War II could have been prevented if other nations had smashed Franco, and his allies, Hitler and Mussolini, in Spain. But he believed that struggle itself gave life meaning.

"If you need a victory, you arent a fighter," he said in 2000, "youre an opportunist."

(N.Y.Times)