At a news conference in her native South Carolina, Essie Mae Washington-Williams said she did not come forward earlier because she didn't want to jeopardize Thurmond's political career and family. "Throughout his life and mine we respected each other. … I was sensitive about his well-being and his career."
Essie Mae Washington-Williams tells the whole story to Dan Rather on 60 Minutes II, Wednesday at 8 p.m. ET/PT.
"I am not bitter. I am not angry. In fact, there is a great sense of peace that has come over me in the past year," she said. "I feel as though a great weight has been lifted. I am Essie Mae Washington-Williams, and at last I feel completely free."
Williams announced last weekend she is the illegitimate daughter of Thurmond, a former segregationist, and Carrie Butler, a maid for the Thurmond family. Thurmond was 22 and Butler was 16 when Williams was born in 1925.
"I knew him beyond his public image," Williams said. "Certainly never did like the idea that he was a segregationist, but there was nothing I could do about it. That was his life."
Williams is a retired teacher living in Los Angeles. She said she has four children, 13 grandchildren and four great-grandchildren.
Thurmond died in June at age 100.
Thurmond's family on Monday said it acknowledges the woman's claim that she is his illegitimate mixed-race daughter.
"As J. Strom Thurmond has passed away and cannot speak for himself, the Thurmond family acknowledges Ms. Essie Mae Washington-Williams' claim to her heritage. We hope this acknowledgment will bring closure for Ms. Williams," the family's lawyer, J. Mark Taylor, said in a brief statement.
Williams had long been rumored to be Thurmond's child, though she had previously denied it. She came forward now at the urging and encouragement of her children, Frank K. Wheaton, an attorney for Williams, said.
Williams told The Washington Post that Thurmond privately acknowledged her as his daughter and had provided financial support since 1941.
In seven decades of politics, Thurmond gained fame and infamy as an arch-segregationist, but he later came to support a holiday for the slain civil rights leader Martin Luther King.
Raised by an aunt, Williams told the Post she first met Thurmond around 1941, when she was 16, and Thurmond called her a "very lovely daughter."
She told the newspaper she received money at least once a year in sessions arranged by Thurmond's Senate staff. Wheaton said the total over the years was "very substantial" but less than $1 million.