Back when Mamie Locke was growing up in Rankin County, Miss., she had a great aunt who seemed to know the whole family story.

Not only could she tell who was who for several generations back but she also remembered where they came from and who they were married to.

Combined with some rare surviving plantation records, that long family memory enabled Locke and her clan to do something not many African-Americans can do — trace their history from modern Mississippi to slave-era Alabama — and then even further back to early 1800s Virginia.

But beyond that they ran into the same brick wall that has bedeviled virtually every black person searching for his or her past. Though they knew from the color of their skin that the trail led back across the Atlantic to the shores of Africa, they had no tangible lead when it came to rooting out their origins among the giant continent's unrivaled proliferation of countries and ethnic groups.

All that changed in 2006, when the Hampton woman swabbed the inside of her cheek for a DNA test that could follow her matrilineal genes back through space and time. Where it landed after spiraling back through generations was in the bloodlines of four different tribal peoples living in the modern West African nations of Gabon and Cameroon.

"In a lot of ways, it was cleansing," says Locke, a state senator and Hampton University educator who will be taking part in several genealogical workshops at a Saturday, June 26, African-American Cultural Forum in Hampton.

"For years, I was always helping other people connect with their past through my work as an archivist. But I was never able to connect with my own."

Locke is only one of many African-Americans expected to take part in the daylong forum, which is being organized in concert with this weekend's Afrikan-American Festival and the city's celebration of its 400th anniversary.

As in years past, one of the primary topics will be African-American genealogy. But the upcoming program has been beefed up by the appearance of Gina Paige, the president and co-founder of African Ancestry, which became nationally known for tracing the lineage of such black celebrities as Oprah Winfrey and Spike Lee.

"African-American history began in Hampton," says forum organizer Pam Croom, referring to the landing of English America's first known Africans at Old Point Comfort in 1619.

"So to have someone as prominent as Gina Paige come here and work with local figures helps us make a real connection — a local connection — to that part of Hampton's history."

Paige and her partner, genetic scientist Rick Kittles, founded their Washington, D.C.,-based company in 2003 after more than a decade of work in which Kittles developed a new way to trace his own African ancestry.

Inspired by an interest that dated to his elementary school years, Kittles began compiling a database of African genetic sequences that enabled him — and ultimately more than 20,000 others — to leap past the gaps in the traditional records and look for matches among nearly 400 ethnic groups spread across 30 different African countries.

Two biogeographical tests — one tracing the maternal line through mitochondrial DNA, the other tracing the paternal line through markers on the Y chromosome — became the primary search tools, producing sequences that could then be compared to more than 25,000 samples.

With a success rate of 99 percent, the company and its $349 tests were featured prominently in a highly rated 2006 public television program —"African-American Lives" — and then again this year when the series returned.

"For African-Americans — we don't know where we came from," Paige says — "unless we do something like this."

Not everybody is as pleased as Locke with this new window on their past.

In about 35 percent of the paternal lineage tests, the sequences indicate European rather than African ancestry — and that mixed-race finding sometimes leads to an emotional response, Paige says.

Other people have reacted with equal distress when the tests refute — rather than confirm — a family's long-held folklore beliefs about its origins.

"I always wanted to know more about my father's side. All we knew was that my grandfather's father was white," Locke says. "But when I asked my brother to take the test, he said he didn't want to know."

Still, for many other African-Americans, including former state delegate Mary T. Christian, the idea of reaching back to a concrete spot on the African continent has a powerful allure.

That's why the Hampton woman, who visited Africa some two decades ago, is so excited about finding out if she once set foot in her ancestral homeland.

She'll be among the folks whose test results will be revealed at the forum.

"Saying you're from Africa doesn't mean anything. There are so many countries, so many tribes, so many cultures," Christian says.

"So it will be interesting to see exactly where I'm from — and if I was there when I visited years ago."

Want to go?

What: African-American Cultural Forum

Where: Crowne Plaza Hotel, 700 Settlers Landing Road, Hampton

When: 9 a.m.-5 p.m. Saturday, June 26

Cost: Free

Info: 727-8311