The biracial daughter of the late Sen. Strom Thurmond defended the former segregationist on Tuesday and said the Rev. Al Sharpton "overreacted" when Sharpton learned he is a descendent of a slave owned by the senator's relatives.

"In spite of the fact he was a segregationist, he did many wonderful things for black people ... I'm not sure that Reverend Sharpton is aware of all the things he did," said Essie Mae Washington-Williams, who was in South Carolina for a speech. "I kind of feel that there was an overreaction."

Professional genealogists working for Ancestry.com found that Sharpton's great-grandfather Coleman Sharpton was a slave owned by Julia Thurmond, whose grandfather was Strom Thurmond's great-great-grandfather. Coleman Sharpton was later freed.

When Sharpton learned of the link, he said: "It was probably the most shocking thing in my life."

Thurmond, of South Carolina, was once considered an icon of racial segregation. During his 1948 bid for president, he promised to preserve segregation. In 1957, he filibustered for more than 24 hours against a civil rights bill.

Sharpton, who ran for president in 2004 on a ticket of racial justice, said he met Thurmond in 1991 with the late soul singer James Brown, who knew Thurmond. Sharpton said the meeting was "awkward."

"I was not happy to meet him because what he had done all his life," Sharpton said.

Thurmond, the nation's long-serving senator, was originally a Democrat but became a Republican in 1964. He softened his segregation stance later in his life and died in 2003, at 100.

Thurmond's children have acknowledged that Thurmond fathered a biracial daughter. Williams' mother was a housekeeper in the home of Thurmond's parents.

A telephone message left Tuesday at Strom Thurmond Jr.'s office was not immediately returned.