Michael Rossman, an organizer of the Free Speech Movement at the University of California, Berkeley, who was later known for his books on politics, society and education, died May 12 at his home in Berkeley. He was 68.

The cause was leukemia, his wife, Karen McLellan, said.

Mr. Rossman was a graduate student in math at Berkeley when the Free Speech Movement burst into being on Oct. 1, 1964. He was among the hundreds of students who massed around a police car that day and the next to stop officers from taking away the civil rights organizer Jack Weinberg. (Mr. Weinberg had been arrested for violating a longstanding university ban on political advocacy on campus.)

A close friend of Mario Savio, the movement’s best-known leader, Mr. Rossman left graduate school in 1966 to devote himself to activism, lecturing on campuses around the country. The Free Speech Movement, which quickly spread to other universities, made political discourse a basic right on college campuses throughout the nation.

Mr. Rossman remained a community activist to the end of his life. For the last three decades, he also taught primary-school science in Berkeley.

In addition to his wife, Mr. Rossman is survived by two sons, Lorca, of Olema, Calif., and Jaime Kaszynski of Olympia, Wash; a brother, Jared, of Redway, Calif.; a sister, Devora Rossman of Mendocino, Calif.; and one grandchild.

As a consequence of his involvement with the Free Speech Movement, Mr. Rossman spent nine weeks in jail in 1967. There, he was assigned to garbage detail, a job far less punitive than his jailers must have imagined.

As Mr. Rossman explained in an essay in “The Wedding Within the War,” he had no sense of smell.