The U.S. state of Georgia executed the only woman on its death row on Wednesday, marking the first time in 70 years the state has carried out a death sentence on a woman, a prison official said.

Kelly Gissendaner, 47, the 16th woman executed in the United States since the Supreme Court reinstated the death penalty in 1976, died by lethal injection at 12:21 a.m. EDT after being sentenced to death for what is known in the state as malice murder for her role in plotting to kill her husband, Douglas, in 1997. Georgia last executed a woman in March 1945, when Lena Baker was killed in the electric chair for murdering her employer. Baker said she acted in self-defense, and Georgia's parole board pardoned her in 2005.

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The state's Board of Pardons and Paroles met on Tuesday to decide whether its refusal earlier this year to commute Gissendaner's sentence to life in prison should stand. Board members were not swayed by her latest appeal for clemency, which emphasized her model behavior in prison and her remorse. Her lawyers also noted she was not present when the crime was committed.

Gissendaner's supporters included her three adult children and a former Georgia Supreme Court justice who says he was wrong to deny one of Gissendaner's earlier appeals.

Pope Francis, who concluded a six-day U.S. trip on Sunday and is an outspoken opponent of the death penalty, had unsuccessfully urged officials to commute her death sentence.

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Gissendaner's scheduled execution was called off in February due to bad weather affecting roads and again in March when officials noticed what they believed was a problem with the injection drug they were about to use.

Women make up less than 2 percent of the country's total death row population, said the Death Penalty Information Center, a nonprofit organization that tracks the issue of capital punishment.