A woman researching her family's history walked into the South Carolina Historical Society when Jane Aldrich was its archivist and asked for help. The woman wanted to find one of her enslaved ancestors in its collections. Aldrich was able to help her find several.

"She was gleaming, thrilled, overwhelmed," Aldrich said. The patron never expected to get that far back in her research.

In addition, Aldrich works with Lowcountry Africana, a web project, to put records that document slaves on the Internet. She and its founder, Toni Carrier, researched Michelle Obama's ancestry for President Barack Obama's first campaign.

Now executive director of the Bunce Island Coalition, Aldrich works to preserve the island off Sierra Leone from which many Lowcountry ancestors embarked. She also is helping a descendant who knows of one such ancestor to find others.

Here is a Q&A with Aldrich on the research:

What does it take to find enslaved ancestors?

Aldrich: One thing you must have is a family trail back to the 1870 federal census, the first to list African-Americans, emancipated by the Civil War, with names. Then, you have to be able to research back to the 1860 census and identify their slave owner, whose plantation records could list the slaves.

Is that easy?

Aldrich: It's much easier if you know what plantation your people came from and if the plantation's records exist. Sales records, inventories, wills or letters that show the enslaved ancestors being exchanged between family members are needed. Those records help to trace the slave from one time to another. Often people assume they know who the slave owner was based on their own last name. That assumption often is incorrect.

How many African-Americans can find such records?

Aldrich: An increasing number. I would not venture a percentage, but for South Carolina, Lowcountry Africana (www.low countryafricana.net) is indexing wills and inventories listing enslaved Africans from Colonial times to 1870. The project is a collaboration with familysearch.org, Footnote.com and the S.C. Department of Archives and History. The records can be found at www.footnote.com and access is free.

How long does it take to trace enslaved ancestors?

Aldrich: It depends on correctly identifying the slaveholders and the slaveholder's record-keeping. Some planters kept extremely detailed records and you can almost go back family to family and get back to where records tell the enslaved person's country of origin. Some may not have organized slaves into families, or mentioned them by name, making it much harder to trace them.

Is it hard to trace those enslaved by small farmers?

Aldrich: Again, it depends on the records. If the small farmer was a good record keeper with a small number of slaves, it could be easier to identify ancestors.

How often are you able to help someone.

Aldrich: We can get half of the people who request help back to the plantation, maybe. And that is usually through a combination of finding their ancestors in Freedman's Bureau (the agency that helped blacks establish themselves as free persons) records and having reliable information about where the ancestors lived before freedom. But detailed records created by a slaveholder are still needed to go beyond that.