But Harding is far from the only president to be accused of having an affair and fathering children from it -- though thanks to this DNA test, his is one of the most provable. Here are five more presidents who, centuries later, still face rumors of having fathered children outside of marriage.
We should mention that historians have found little evidence that our nation's first president fathered any children at all, actually. He and his wife, Martha, had no children, suggesting he was sterile, possible from a case of smallpox.
But in 1999, The New York Times' Nicholas Wade reported that descendants of a slave named Venus who lived on a family's estate were asking for a DNA test to prove they were descendants of George Washington.
Historians disagreed -- but as the article notes, historians also doubted Thomas Jefferson's relationship with one of his slaves until a DNA test proved otherwise.
Accusations that our nation's third president had fathered children with one of his slaves, Sally Hemings, arose during his first term in office.
His wife, Martha had died while Jefferson was vice president, and Jefferson, of course, owned a vast plantation in Virginia.
From the official Jefferson Monticello estate:
"[The Thomas Jefferson Foundation] and most historians believe that, years after his wife’s death, Thomas Jefferson was the father of the six children of Sally Hemings mentioned in Jefferson's records, including Beverly, Harriet, Madison, and Eston Hemings. "
A DNA test in 1998 linked the two and provided further evidence they had a family together.
William Henry Harrison
The first president to die in office -- after just 32 days -- had 10 children with his wife, Ana.
But while writing a biography of the 20th-century African-American leader Walter Francis White, historian Kenneth Robert Janken uncovered a possible relationship between Harrison and one of his slaves, Dilsia, whose ancestors claim she had six children with him and that four were sold a Georgia plantation.
One of those ancestors is believed to potentially be White's mother, Madeline Harrison.
The nation's first vice president to become president -- upon the death of Harrison -- fathered more children than any other president so far: eight with his first wife and seven with his second.
But an abolitionist writer accused Tyler of also fathering children with slaves from his Virginia estate -- and then selling some of them. Unlike Harding, though, there's no direct proof, writes Edward Crapol in his 2006 biography John Tyler, "The Accidental President."
During his first campaign for president, the Buffalo Evening Telegraph broke a story that "many in upstate New York had long known to be true," writes Angela Serratore in The Smithsonian Magazine:
"[Ten] years earlier, a woman named Maria Halpin had given birth in that city to a son with the surname Cleveland and then been taken to a mental asylum while the child was adopted by another family."
Republicans seized upon the news reports to damage a man who until then had a sterling reputation. They created a scurrilous chant:
"Ma, ma where's my pa? Gone to the White House, ha ha ha."
Cleveland's campaign had no choice, Serratore writes, but to admit that he and Halpin were "illicitly acquainted," but he maintained it happened while Cleveland was a bachelor.
Halpin was separated from her son, whisked away to a mental hospital and later told publications that her affair with Cleveland wasn't consensual. Cleveland denied the allegations and, of course, won his election.
Think we missed anyone? The comments section awaits.