Although Johnson and Smith lived in the same rural county for years, they have never spoken about it: that sickening moment in 1971 when Smith ran over Johnson's daughter, Margaret Ann Knott, and killed her during a civil rights protest.
"I don't hate him in any way," Johnson said, explaining that she did not want her surviving children to live with hate.
The civil rights movement dragged on longer in Choctaw County than many other places, well into the 1970s. Near the Mississippi state line in the timber country of western Alabama, schools desegregated after protests and a federal lawsuit in the late 1960s. Not until later did black people become fed up enough to take action over economic inequality in the county, where the courthouse square has two monuments to Confederate dead, including a statue that looks out over the spot where Margaret Ann Knott died.
Blacks worked as janitors and store stockers in the county seat of Butler, but whites always got the higher-paying positions. Whites held all elected offices in the county of 16,500 people, which is about 55 percent white.
When blacks began organizing protests there, Johnson already was a respected teacher with deep community ties through schools and church. She was a natural to help lead a push for better jobs and wages.
Longtime residents remember a hot summer of protests, with blacks filling the streets and boycotting stores. Dozens of state troopers were called at one point amid a rumored plan to burn down the courthouse.
To judge by the local newspaper, however, all was calm. The Choctaw Advocate didn't cover the protests until after that Saturday when Gladden Smith drove into town.
Smith, a south Alabama native who was assigned to Butler in his job as an agent with the U.S. Agriculture Department, had been working out in the county that morning of Sept. 11, 1971. He drove into the town in his government pickup, stopped at the office and got into his personal car before heading toward home through the courthouse square.
"I remember coming through the intersection and seeing people over to the side," Smith, 71, told The Associated Press during a recent interview at his home in rural Escambia County, near the Florida line. "I didn't know what I was getting into."
Demonstrators were staging a sit-in in the middle of an intersection ahead of him on the other side of the square. Pictures taken by the town photographer, Jack Hopson, show people everywhere.
Smith drove through one intersection and then another, where he turned left. Witnesses said people were chasing the car and hitting it as he approached the intersection where Knott and other protesters sat in the road.
Smith was worried the crowd was after him, but he stopped at a red light.
"They were rocking that car trying to turn it over and everything," he said. "You get caught in a life-and-death situation and you have to make a decision."
Smith said he eased forward. Demonstrators moved, he said, and then he felt the thud.
"I knew I had hit something, but I thought it was a leg," he said.
Seated directly beside Knott on the pavement as the car approached, demonstrator Willie S. Jackson had a different view.
"People started hollering that a car had broken the line," said Jackson, now 64. "I stood up and sure enough a car was coming with people running behind it."
Before Jackson knew it, the front bumper of Smith's car was against Knott's back. Overweight, she was struggling to get up after others already had fled, Jackson said.
A front tire rolled over Knott, and the vehicle seemed to stand up in the air, said Jackson. People grew frantic.
"They were beating on it. I was, too. We were trying to get him off her. We would have lifted the car off her, but then he gunned it," said Jackson.
Smith doesn't remembering accelerating quickly. The sheriff's official account — printed afterward in the county newspaper — said only that Smith "eased through the intersection at a safe rate of speed." Some said Knott was pushed down into the car's path, but nothing was ever proven.
Smith said he saw a police officer just up the street and stopped. He told the man what had happened and drove home but was soon in the county jail.
Knott was rushed to the hospital, where she died before sunset.
"She just kept saying, 'I died for freedom, I died for freedom,'" Jackson recalled.
Carrie Johnson had been at a church preparing for the next civil rights demonstration when her daughter was fatally injured; she got the news later in a phone call.
Johnson, now 86 and retired from the school system, wanted Smith prosecuted for something, although she wasn't sure what.
A demonstrator signed a warrant charging Smith with murder, but Smith was quickly released on bond. Yellowed courthouse records show prosecutors called as many as 53 witnesses to testify before a mixed-race grand jury that considered a charge of second-degree manslaughter and declined to indict him.
The criminal case was concluded by the end of the month, and no one has been prosecuted since in Knott's death.
Smith said his insurance company paid a $10,000 settlement.
Johnson was deeply wounded, but she thought of her other five children, including Margaret Ann's twin sister, Mary Ann. Johnson feared what anger or a quest for vengeance might do to Mary Ann and her sons, plus the unborn boy she was carrying at the time.
So Johnson, a Christian, said she made the only possible decision by forgiving Smith and trying to put herself in the driver's seat that day.
"I've tried to tell my children this, and other people: Imagine yourself (as a white) in a crowd of blacks and they are taunting and shaking your car and rocking your car," she said. "I don't hold it against him because I really don't think he deliberately did it."
Nearly 120 miles away at his rural home ringed by pine trees and azaleas, Smith wishes things were different.
"If I hadn't got up that morning I would have probably been a lot better off," he said. "But it happened."
Smith, who retired in 2000, still owns a home in Butler but only visits occasionally. Yet he and his wife and their three sons, now grown, spent much of the last four decades in Choctaw County.
Smith, a deacon in his church, said the family remained despite taunts and threats directed at his sons while they attended integrated public schools. They stayed despite threatening telephone calls and cars that drove slowly by their home.
"It was either stay there or run," he said. "What I tried to do was do a little bit extra or whatever for the black community. I was trying to do my job, but I was also trying to show that I didn't mean no harm."
Johnson also stayed, at one point serving with Smith's wife on a school committee. Hundreds attended Knott's funeral, and leaders formed a biracial commission which reached an agreement that ended the demonstrations within a week.
Donors gave money for a $4,700 granite monument meant to be erected outside the courthouse in memory of Knott, but the white-controlled commission refused permission to install it. Chipped and stained, the three-piece memorial now lies outside Richard Moore's stone-cutting shop in Meridian, Mississippi.
Johnson said she'd like to talk to Smith, to tell him she doesn't want him prosecuted and doesn't hold him responsible for her daughter's death.
Smith demurs at the idea, saying he made his peace with God.
"I ask the Good Lord to help put behind me the things I can't change," said Smith.