Howard Zinn, historian and shipyard worker, civil rights activist and World War II bombardier, and author of “A People’s History of the United States,” a best seller that inspired a generation of high school and college students to rethink American history, died Wednesday in Santa Monica, Calif. He was 87 and lived in Auburndale, Mass.

The cause was a heart attack, which he had while swimming, his family said.

Proudly, unabashedly radical, with a mop of white hair and bushy eyebrows and an impish smile, Mr. Zinn, who retired from the history faculty at Boston University two decades ago, delighted in debating ideological foes, not the least his own college president, and in lancing what he considered platitudes, not the least that American history was a heroic march toward democracy.

Almost an oddity at first, with a printing of just 4,000 in 1980, “A People’s History of the United States” has sold nearly two million copies. To describe it as a revisionist account is to risk understatement. A conventional historical account held no allure; he concentrated on what he saw as the genocidal depredations of Christopher Columbus, the blood lust of Theodore Roosevelt and the racial failings of Abraham Lincoln. He also shined an insistent light on the revolutionary struggles of impoverished farmers, feminists, laborers and resisters of slavery and war.

Such stories are more often recounted in textbooks today; they were not at the time.

“Our nation had gone through an awful lot  the Vietnam War, civil rights, Watergate  yet the textbooks offered the same fundamental nationalist glorification of country,” Mr. Zinn recalled in a recent interview with The New York Times. “I got the sense that people were hungry for a different, more honest take.”