Kenneth Lee Boyd, set to die at 2 a.m., spent the day receiving visitors, including two sons who watched him gun down their mother and grandfather in 1988.
"He would love to live and he would love to have the governor and the courts step in, but he's also facing the possibility that won't happen," said Boyd's lawyer, Thomas Maher.
But Governor Mike Easley has denied to offer clemency to a man who killed his wife and father-in-law.
In a statement, Easley said that after reviewing the facts and circumstances of the crimes and convictions, he found no compelling reason to grant clemency and overturn the unanimous jury verdicts affirmed by the courts.
Boyd's attorney, Thomas Maher, said that his client handled the news of Easley's decision well.
Larger-than-normal crowds of protesters were expected at the prison in Raleigh, and vigils were planned across the state. Prison officials planned to tighten security.
The U.S. Supreme Court and the 4th U.S. Circuit Court of Appeals rejected appeals by Boyd's lawyers Thursday.
The defense also sought clemency from Democratic Gov. Mike Easley, but there was little to suggest Boyd would get it. The governor granted condemned inmates clemency only twice in nearly five years in office, during which time 22 inmates have been put to death.
Boyd, 57, did not deny that he shot and killed Julie Curry Boyd, 36, and her father, 57-year-old Thomas Dillard Curry. Family members said Boyd stalked his estranged wife after they separated following 13 stormy years of marriage and once sent a son to her house with a bullet and a threatening note.
During the slayings, Boyd's son Christopher was pinned under his mother's body as Boyd unloaded a .357-Magnum into her. The boy pushed his way under a bed to escape the barrage. Another son grabbed the pistol while Boyd tried to reload.
The U.S. Supreme Court in 1976 ruled that capital punishment could resume after a 10-year moratorium. The first execution took place the following year, when Gary Gilmore went before a firing squad in Utah.
For his last meal, Boyd requested a New York strip, medium well, a baked potato with sour cream, salad with ranch dressing, a roll with butter and a Pepsi.
Boyd told The Associated Press in a prison interview that he wants no part of that infamous distinction. "I'd hate to be remembered as that," Boyd said Wednesday. "I don't like the idea of being picked as a number."
The 1,001st could come Friday night, when South Carolina plans to put Shawn Humphries to death for the 1994 murder of a store clerk.
In Boyd's plea for clemency, his attorneys argued his experiences in Vietnam — where as a bulldozer operator he was shot at by snipers daily — contributed to his crimes.
As the execution drew near, Boyd was visited by his three grown sons, who had not met face-to-face with him since he was sent to death row more than a decade ago.
"He made one mistake and now it's costing him his life," said son Kenneth Smith, 35, who visited with his wife and two children. "A lot of people get a second chance. I think he deserves a second chance."
Smith's wife planned to witness the execution, as did two other family members of the victims whose relationship was not immediately clear. Boyd's lawyer, a small group of law enforcement officials and journalists also planned to watch through the thick, twin glass panes between the viewing room and the death chamber.