Dylann Roof's racially motivated murders of nine black churchgoers have brought predictable calls for new restrictions on the right to keep and bear arms. How ironic this is we shall soon see.

Advocates of gun rights argue that the best way to prevent such atrocities is for would-be victims to arm themselves; killers will break gun laws without hesitation (though Roof obtained his .45-caliber handgun legally), so legal obstacles to gun ownership only impede the innocent. Relying on the police for defense is futile—or worse.

This argument persuades few who are committed to "gun control" (a misnomer because law-abiding people, not guns, are subject to control). But those who demand it while grieving over the racist massacre at Emanuel AME church in Charleston, S.C., ought to understand that "time and again, guns have proven pivotal to the African American quest for freedom."

That sentence is found in Charles E. Cobb Jr.'s important book That Nonviolent Stuff'll Get You Killed: How Guns Made the Civil Rights Movement Possible.

Guns made the civil rights movement possible? What about the philosophy of nonviolence embraced by most prominent civil rights leaders, such as Martin Luther King Jr.?

As Cobb, a journalist and veteran civil rights activist, explains, for many civil rights activists in the South, nonviolence did not rule out "armed self-defense," which meant keeping firearms. "In these communities, where the law was generally weighted against them, armed self-defense was a natural response to white terror," he writes.

True, many activists believed in a turn-the-other-cheek strategy. But others rejected strict passivism. "Whether the question was one of picking up a gun in response to attack by night riders," Cobb writes, "or of curling one's body tightly and protectively while being assaulted by a mob during a lunch-counter sit-in, or of shielding an elderly person under attack for trying to register to vote, the decision of what to do centered not on the choice between nonviolence and violence but on the question of what response was best in each situation." As one Mississippi activist and farmer, Hartman Turnbow, put it after scaring off night riders with his gun, "I wasn't being non-nonviolent; I was just protecting my family."

Guns of course pervaded the South before the civil rights movement, and this was true of black culture too. Moreover, many black war veterans came home with guns, determined to win their freedom. As the black freedom movement emerged after World War II and the Korean War, it was only natural for guns to be seen as important in the defense against the daily threat posed by the Ku Klux Klan and other white supremacists.

Cobb's book is filled with accounts of incidents in which brutal racists were persuaded to retreat by black men armed and ready to defend themselves and their families. For example, "There is … no shortage of examples of black resistance to the vicious and violent white supremacy that continued to prevail in Louisiana as CORE [Congress of Racial Equality] organizers began their work." Guns were no guarantee against white aggression, but Cobb's message is that more blacks would have been killed had they been unarmed.

This book taught me, among other things, that 1) Martin Luther King's home in the 1950s was "an arsenal" and was always guarded by armed men, 2) that King in 1956 applied for a concealed-carry permit (and was turned down), 3) that Daisy Bates, who advised the Little Rock Nine, carried a .32-caliber handgun in her purse, 4) and that Medgar Evers always was armed. (Evers of course was murdered; guns are no panacea.)

Cobb understands that "America's first gun control laws … were designed to prevent the possession of weapons by black people," and he writes that "it can easily be argued that today's controversial Stand Your Ground right of self-defense first took root in black communities." (Whites expected blacks to "back down or submit—never to stand up for themselves.") He concludes, "There was a time when people on both sides of America's racial divide embraced their right to self-protection, and when rights were won because of it. We would do well to remember that fact today."

This piece originally appeared at Richman's "Free Association" blog.