Moody has spent more than 20 years awaiting the death penalty after he was convicted of mailing a bomb that killed United States judge Robert Vance in December 1989.
The non-profit Death Penalty Information Center says Moody became the oldest inmate put to death in the United States since the resumption of US executions in the 1970s.
Moody was convicted in 1996 for the murder of federal Judge Robert Vance in Birmingham, Alabama.
Moody is assumed to contest to SCOTUS once more Thursday.
According to AL.com, the lethal injection began at 8:16 p.m.at the Holman Correctional Facility in Atmore and prison officials placed his time of death at 8:42 p.m.
He had also murdered Georgia civil rights lawyer Robert Robinson.
Two other mail bombs were intercepted and defused before they exploded, including one at the office of Jacksonville, Florida, office of the National Association for the Advancement of Colored People (NAACP). But, later he was indicted on capital murder charges 1996.
"He believed the Democratic Party should be open and not be the party of George Wallace and the Dixiecrats", LaPierre said. "Had my Dad been murdered, I would want to know who had done it", Moody wrote.
Moody maintained his innocence, and his attorneys argued in court filings and a clemency petition to Alabama Gov. Kay Ivey that his age and vein condition would make lethal injection more hard.
Judge Vance's son, Robert S. Vance Jr., said on Thursday that he has never forgiven Moody because "he has not acknowledged any remorse or any acknowledgment that he was guilty", according to the Associated Press, adding that Moody fit the profile of a psychopath. Package bombing done by Moody was a revenge story on the legal system.
Gov. Kay Ivey and Attorney General Steve Marshall both released statements following the execution.
"He was a great judge, a great lawyer before that, and a great father", he said earlier as the execution loomed.
The appeal to save Moody's life had been filed with the US Supreme Court. They also argued that Vance was personally opposed to the death penalty.
"But he also made clear that as a judge, he has to follow what the law dictates and put aside his personal views, and he had to do that several times sitting as a judge", Mr Vance said of his father.
The nation's highest court issued the stay order Thursday evening on behalf of 83-year-old inmate Walter Leroy Moody as it considered his requests to block the lethal injection procedure.
Moody turned down a final meal from the state and instead ate two Philly cheese steak sandwiches and drinking two Dr Peppers during a visit with friends and attorneys at the correctional facility before being executed.