Taylor Branch's three-volume biography of the Rev. Dr. Martin Luther King Jr. is variously described as masterful, epic, a narrative tour-de-force -- the definitive story of the civil rights movement in America's past century.

These days, though, the Pulitzer Prize-winning author is mostly looking ahead -- even as he plans to deliver a speech Sunday at Temple Sinai in Squirrel Hill that will reach back into that convulsive history to weave connections, pull larger themes out of massive detail and, he hopes, deliver some clarity about the meaning, and timing, of Barack Obama's presidency, two generations after King's death.

"In the Bible, 40 years is always a significant number," Branch said in a telephone interview last week from his home in Baltimore. "It's the number of years Moses wandered in the desert after parting the waters, and I think it's somehow significant that Obama is taking office 40 years after Martin Luther King died."

It's especially important to take stock now, he says, because pervasive myths persist about the transformational nature of King's era, which, quite simply, are not true.

"There is a lot that race relations have not achieved in the time since King's death," Branch said, "and I think many people are particularly out of phase with what was accomplished and what was not. The first thing a citizen needs is clarity about our history and what it means."

Branch's speech, which is open to the public, is being sponsored by the Pamela K. Wiles Fund for Interfaith Understanding, which was founded to honor Wiles, a Pittsburgh lawyer who died in 1998.

She and her husband, the late Neil Siegel, who died in October 2007 leaving two teenage sons, were members of Temple Sinai in Squirrel Hill. As an interfaith couple, they represented the highest values and aspirations of this reform Jewish synagogue, said Rabbi James Gibson, the synagogue's senior rabbi.

Siegel's oldest son, Eli, 18, will give an introduction.

The choice of Branch was particularly apt, Gibson added, because his trilogy -- "Parting the Waters" (1988), "Pillar of Fire" (1998) and "At Canaan's Edge" (2006) -- highlighted efforts by "a coalition of different religious leaders to come together in the face of implacable hatred and stand up for their highest religious values."

To that end, the synagogue has invited representatives of the Pittsburgh Theological Seminary's Metro-Urban Institute, the East End Cooperative Ministries and the Pittsburgh Interfaith Impact Network to attend, along with members of Christian Associates, a leadership group of all local Christian judicatories.

Indeed, nearly 1,000 religious people of different faiths "dropped everything in their lives and jumped on a plane when the call came to march in Selma" in 1965, Branch noted. "The religious element was important in the manpower of the movement," not just King's message, "which nonetheless framed spiritual challenges in political terms, and political challenges in spiritual ones."

During the 1950s and 1960s, religious people were perhaps the only ones who thought it might be possible to change race relations, Branch said. They came from Methodist camps, Quaker groups, Jewish ethical study groups, "people who had studied ecumenical nonviolent change like Gandhi," he said. "These were the few people willing to do something quite frightening, venture across town and talk about whether this was possible, in private homes or in the YMCAs -- the only public places where this was allowed -- at the time. It was a fearsome, hopeless cause, and they became pariahs, their children shunned at school."

Those of the Jewish faith, the young, in particular, were on the front lines. "Jewish kids were overrepresented during 1964's Freedom Summer," said Branch, most notably Andrew Goodman and Michael Schwerner, civil rights workers from New York's Jewish community who were killed in Philadelphia, Miss., by the Ku Klux Klan along with James Chaney, a young black man.

Rabbi Abraham Heschel, a distinguished Jewish theologian and a foremost authority on the Hebrew prophets, spoke out strongly against racism and marched with King in Selma, later famously saying, "When I marched in Selma, my feet were praying."

For years, Branch hoped his massive civil rights history would reach a wider audience, but plans for a filmed version repeatedly fell through. Today, though, a proposed HBO miniseries -- along the lines of the recent, highly successful adaptation of David McCullough's "John Adams" series -- is in development. He is keeping his fingers crossed, he said.

In the fall, he'll also be publishing a memoir about his time spent in the White House with President Bill Clinton, who asked him to record sessions for historical purposes -- in secret.

"The Clinton Tapes: Wrestling History With the President," to be published by Simon & Schuster, will contain highlights of those late-night conversations -- 3,000 to 4,000 pages' worth -- "and what it was like to do this, the feel and the flavor of it. A lot of my reactions about being in the White House are in this book. Chelsea would come in and say goodnight, he'd ask my opinion about something, and I'd think, is it my first duty to get the history down or act as an adviser or a friend?"

"Usually I'd get a call in the morning," Branch said, although sometimes the calls would come as late as 5 p.m., asking him to come to the White House that night. "It was a secret project and the president didn't want staff around because he was worried that something would leak and all the recordings would be subpoenaed. They'd clear me in the park on the south grounds, and I'd come in under the Truman Balcony and go into the residence. The president might sit and talk for one, two or three hours about what had occurred that day. Sometimes our conversations were cut short because something happened -- there were air strikes once. It's not like the world didn't know that the presidency was off-limits during that time," Branch added with a laugh.

Branch will appear on Sunday at 7:30 p.m. at Temple Sinai, 5505 Forbes Ave., Squirrel Hill. For more information call 412-421-9715 by Friday or check the synagogue's Web site at templesinaipgh.org.