Last year was a tipping point in 40-year anniversaries of black history events. In 2004 we looked back at the Civil Rights Act of 1964. But 2005 was the anniversary of both the Voting Rights Act and … the Watts riot. And this year is the 40th anniversary of the founding of the Black Panthers. Somehow it’s hard to nail just what to celebrate on this one.

Why is it that black history seems to fall apart in the mid-1960s? In “Waiting ‘Til the Midnight Hour” (Henry Holt, 400 pages, $27.50), Peniel Joseph proposes that it doesn’t, that the Black Power era was more than “a cautionary tale featuring gun-toting militants who practiced politics without portfolio.” He begins with the roots of black nationalism in the 1950s and their coalescence around Malcolm X, in a time so distant from ours that even a black nationalist publication was called something as antique as the Illustrated News. Mr. Joseph goes on to cover Stokely Carmichael as the head of the Student Nonviolent Coordinating Committee, imprinting the term Black Power on the national consciousness, and finally covers the rise and fall of the Black Panthers.

All concerned devolved into arcane battles between pan-Africanists who rejected white assistance and Marxists who welcomed it. It didn’t help that many Panthers were post-adolescent ex-hustlers, in contrast to seasoned and thoughtful celebrities such as Huey Newton and Elaine Brown. Too often Panthers solved problems the “street” way: In January 1969, two of them, Bunchy Carter and John Huggins, were killed in a battle with a rival organization on the UCLA campus!

Four months later, on May 20, 1969, a New Haven Panther and one-time Great Society employee, Warren Kimbro, killed a 19-year-old new recruit, Alex Rackley, on the orders of a rageaholic superior who had irrationally decided that Rackley was an FBI informant. Kimbro pleaded guilty and went to prison.The co-founder (with Newton) of the Panthers, Bobby Seale, was mistakenly indicted for ordering the murder, while Huggins’s widow, Ericka, who had joined the chapter and been present when their fellow Panthers tortured Rackley before his death, was tried alongside Seale as an accomplice. Their trial, which Douglas Rae and Paul Bass cover in “Murder in the Model City” (Basic Books, 322 pages, $26), helped radicalize the Yale student body.

The FBI had been trailing Carmichael and the Panthers almost around the clock. They played Panthers against one another by forging notes. The men who had shot Huggins were, in fact, FBI informants, and the FBI likely knew that Rackley was to be killed. Because of all of this, Messrs. Rae and Bass believe “liberalism became a dirty word in the country.” Yet the line from Kimbro’s observing some seamy episodes in Great Society administration to his shooting an innocent in the head and leaving him in a swamp is not a straight one. Although the authors’ chronicle of Kimbro’s life shows a marvelous person in many ways, even they cannot pretend that the System turned him astray, nor that the Panthers would have forged a revolution if only COINTELPRO had stayed out of their way.

The ultimate truth is that Black Power was, from the outset, a mess. What exactly was it? Carmichael once ventured “the coming together of black people to elect representatives and to force those representatives to speak to their needs.” But his book-length manifesto, “Black Power,” makes only vague references to “parallel community institutions” with no concrete proposals.

Instead, the most consistent strain in Black Power was calls for violence.The politically correct view is that the alarm this raised was racist or “overblown,” as if black people serving breakfast to the poor were senselessly demonized for being black and articulate. And yes, the Panthers did serve breakfast and did other “some good things” that their defenders regularly bring up today. But the rhetoric that looks like quaint lingo today came off otherwise when it was on the evening news. Some was stark (“If America don’t come around, we’re gonna burn it down”), some abstract (Amiri Baraka’s call for “poems that kill”), but still. As Messrs. Bass and Rae note, Kimbro has since said, “If I was in law enforcement and somebody was spouting ‘revolution’ and all that stuff, I’d want to know what they were doing, too.”

To be sure, Kimbro goes on to criticize the FBI for encouraging the Panthers to kill rather than stopping them, and he’s right. But the rhetoric is even more disappointing today because of its insincerity. Despite Malcolm X’s famous upraised fist, after the Los Angeles police murdered Black Muslim Ronald Stokes in 1962, the Nation of Islam did not respond with a race war. Nor ever did the Panthers. The tough talk was theatrical — but there wasn’t much behind the curtain either.

In real life, Black Power was especially long on conferences. The Grassroots Conference of 1963 was where Malcolm X designated certain blacks as “house slaves.” There was the Congress of African People’s Conference of 1970. The National Black Political Convention of 1972 imprinted “black nationalism” as a mainstream term. But it’s hard to glean what these events added up to besides a mood. Again and again Black Power yelled “Let’s go!” and then just sat there.

Writerly convention requires Mr. Joseph to identify a more substantial legacy. He covers Mr. Baraka’s helping elect Kenneth Gibson as Newark’s first black mayor, and claims that this “represented the potential for a national movement for Black Power.” Thirty-six years later, one wonders what Newark’s new mayor, Cory Booker, would have to say about that. Otherwise, Mr. Joseph has Black Power sparking “cultural pride,” which would mean nice things like the “Color Me Brown” coloring book (a treasured possession of my childhood) and more questionable ones such as Swahili, spoken by no slaves in the United States, being treated as black America’s “native language.”

But Black Power left behind things more significant. Black Power lives on today in the notion that authentic black people are ever waiting for a cathartic moment when white America “realizes” some “truth” about our racist past. Hence the reparations distraction. Black Power taught us that there is something deeply “black” about being lustrously, implacably angry. Hence black ministers at Coretta Scott King’s funeral hollering anti-Republican rhetoric, or black academics celebrating “gangsta” rap as a sophisticated political statement.

Black Power also has its echoes in the glowing blurbs from heavy hitters, white and black, on Mr. Joseph’s book jacket — a multihued community of scholars of like politics who would praise to the heights almost any book he wrote. These blurbs imply an authoritative and insightful chronicle, when the book is more of a dutiful museum tour. It is a rare example of a book that would ideally be twice as long, and the prose is too ordinary to carry it on narrative zing.

Meanwhile, Messrs. Rae and Bass’s story actually is the “white-knuckle” journey the ad copy promises. The writing is captivating — I kept forgetting I wasn’t actually present on the Green at Yale in 1970 watching the National Guard come to quell the protests before the Seale-Huggins trial.

Then again, I’m glad I wasn’t. The anniversaries say it all: Next July, it will have been 40 years ago that Newark, with all of its “potential,” burned amidst chants of “Black Power!” (with Detroit following a week and a half later). These books teach us about a time when too many people fell for the idea that performative fury and political activism are the same thing. We struggle still with the havoc, distraction, and waste wrought by that fallacy.

Mr. McWhorter is a Manhattan Institute senior fellow in public policy, and a contributing editor to City Journal.