WASHINGTON — The biracial daughter of the late U.S. Sen. Strom Thurmond confronted her father more than once over his racist politics, but she cherished their relationship and ignored pleas from family to expose her true lineage.

“For all his bluster, for all his racist campaign posturing, I somehow couldn’t dislike him the way I wanted to.”

So writes Essie Mae Washington-Williams, 79, in “Dear Senator.” The autobiography is co-authored by William Stadiem and will be released next month by ReganBooks, a division of HarperCollins.

The daughter of the longtime champion of segregation and his family’s black maid has remained quiet since she revealed the secret of her birth a year ago — six months after Thurmond’s death.

“Dear Senator,” which takes its title from the way she addressed letters to Thurmond, answers many of the questions that have swirled around a relationship kept secret for nearly eight decades.

Years could go by between meetings, but Thurmond and Washington-Williams saw each other at least a dozen times over his lifetime — in Philadelphia when he returned from World War II; at what is now S.C. State University, the black college he paid for her to attend; and in his Senate office in Washington, where she was introduced as a family friend.

It bothered her that he rarely touched her beyond a handshake, and that even privately only a few times called her “daughter.”

“How does it feel to be the daughter of the governor?” Thurmond asked her on a visit to S.C. State.

Credited as governor, from 1947 to 1951, with improving education for blacks in South Carolina and speaking out against lynching, Thurmond assumed a different mantle as a national politician. He:

• Ran for president in 1948 on the segregationist States Rights “Dixiecrat” ticket

• Set a record with the longest filibuster in Senate history — 24 hours and 19 minutes — railing against the Civil Rights Act of 1957

• Once said, “There’s not enough troops in the Army to force the Southern people to break down segregation and admit the Negro race into our theaters, into our swimming pools, into our homes, and into our churches.”

“I wasn’t sure if this was my father talking or the ghost of Adolf Hitler,” Washington-Williams wrote.

She brought up the hypocrisy of his private and public relationships with blacks at least once. In 1964, then the wife of a civil rights lawyer and the mother of four children, Washington-Williams stopped by Thurmond’s Senate office. “If you mean what you say,” she stammered, “how could you ... how could you ... love ... my mother?”

“He didn’t speak for the longest time. He just looked like the wind had been punched out of him. It was a question he never expected to be called upon to answer. And he didn’t. He kept silent.”

The author, a retired Los Angeles schoolteacher, describes a covert romance between Thurmond and her mother, Carrie Butler; he was 23 and she was 15 when they met.

Taken from South Carolina to be raised by Butler’s sister in the Pennsylvania steel town of Coatesville, Washington-Williams didn’t learn Butler was her mother until she was 13.

When Washington-Williams was 16, and for the first time visiting her family in Edgefield, Butler took her to the office of attorney Strom Thurmond and introduced him as her father.

Washington-Williams had no idea that her father was a white man, not to mention one of the most powerful in town.

She was stunned and speechless, but noticed that Thurmond’s hand lingered on Butler’s.

“They were in love, clearly in love.”

Washington-Williams’ husband, and later her children, pressured her to reveal Thurmond. She could strike a blow, they said, against those who spoke and voted against racial equality. Julius Williams called the thousands of dollars Thurmond had given his wife over the years “hush money.”

But she wouldn’t speak until Thurmond died.

She wrote that the money was the only way he knew how to express affection toward her.

“It’s not that Strom Thurmond ever swore me to secrecy,” she wrote. “He never swore me to anything. He trusted me, and I respected him, and we loved each other in our deeply repressed ways, and that was our social contract.”

Washington-Williams called herself “finally free” when she went public last year.

Since then, and on the basis of her patrimony, she has applied for membership in the United Daughters of the Confederacy. She is also trying to claim some of Thurmond’s estate.

Valued at $1.48 million, most of it was left to Thurmond’s three surviving white children, and none to Washington-Williams.

Attempts to reach members of Thurmond’s South Carolina family were unsuccessful Friday.

Reach Markoe at (202) 383-6023 or lmarkoe@krwashington.com.