Americans widely believe that George Washington had wooden teeth.

But his dentures were, in fact, constructed from “chunks of ivory from hippopotamuses, walruses, and elephants,” along with teeth from a more diabolical source — his own slaves.

“At the age of eleven, he inherited ten slaves from his father, and over the next 56 years, he would sometimes rely on them to supply replacement teeth,” writes Alexis Coe in her new biography, “You Never Forget Your First: A Biography of George Washington” (Viking), out now.

“He paid his slaves for their teeth, but not at fair market value, [paying] two-thirds less than . . . offered in newspaper advertisements,” writes Coe, a consulting producer for “Washington,” the three-part miniseries premiering tonight on The History Channel.

Coe’s book delves into how Washington mistreated his slaves, lied to incite a battle and generally disappointed the Founding Fathers, countering his long-held image as an honest man “who cannot tell a lie.”

A slave named Isaac once told of an incident where Washington ordered him to cut a log. But Isaac was unable to chop it to Washington’s exact specifications.

In response, Washington “gave me such a slap on the side of my head that I whirled round like a top & before I knew where I was Master was gone,” Isaac later told one of Washington’s nephews.

When he was traveling, Washington made sure his slaves toiled from sunrise to sundown, six days a week, kept in line by “overseers” who wielded whips and hickory sticks, a system he found “very proper.”

During Washington’s first presidential term, when he lived in Philadelphia, the state of Pennsylvania passed a law that would have led to his slaves obtaining their freedom. He wrote to a relative that “the idea of freedom might be too great a temptation for them to resist . . . I do not think they would be benefitted by the change.”

For the most prized of his slaves, he took advantage of a loophole in the law: Slaves would only be freed if they remained in the state for six months, so he arranged for his most valued slave to travel to Mount Vernon, Va., every six months, officially keeping him as his property.

When that slave escaped with another in 1797, Washington was adamant they should be captured and returned to him. One was never found. The other, located in the free state of New Hampshire, agreed to return under certain conditions, including that she would never be sold. When Washington learned that she tried to set terms, he went “apoplectic.”

“Such a compromise is totally inadmissible,” he wrote to the man he’d hired to find her. “However well disposed I might be to a gradual abolition . . . it would neither be politic or just to reward unfaithfulness.”

Coe notes that Washington never freed a slave during his lifetime, nor did he do anything to free them as president. And while he claimed to be principled against selling people “as you would do cattle in the market,” he did so on at least three occasions — including once to a man in the West Indies, where slavery was known to be a special kind of hell.

Washington knew that the West Indies “would bring about a brutal change in their lives,” Coe writes, since “they would likely work on sugar plantations under overseers who were quick to use their whips; their diets would be poor, their medical care worse, [and] they were virtually guaranteed a premature death.”

Coe also takes aim at Washington’s reputation as a brilliant military strategist, noting that he lost more battles than he won, and that as a young soldier, he committed a blunder so egregious that it ignited a global conflict.

‘Too illiterate, unlearned, unread for his station and reputation.’ - Fellow Founding Father John Adams, on George Washington’s eight years as the nation’s first commander in chief

At 22, Washington was a major in the Virginia militia, which then fought on behalf of the British crown.

Robert Dinwiddie, the British governor of Virginia, believed the French had set up camp on British territory, so in 1753 he assigned Washington to accompany local Seneca tribe allies to the French fort to assess the situation.

Dinwiddie was clear this was to be a diplomatic mission, and “urged discretion and caution.”

But Washington intentionally inflamed the situation. Knowing that the Seneca chief, Tanacharison, believed that the French had “captured, cooked, and eaten his father,” Washington told the chief and his soldiers that the French intended to kill them. He later wrote that this manipulation “had its desired effect.”

When their party arrived at the French camp, a battle erupted. Ten French soldiers, including the commander, Joseph Coulon de Jumonville, were killed, and 21 were captured.

But the French insisted in an official report that their mission had been a diplomatic one with no intent for battle, a claim confirmed by a letter found on de Jumonville’s corpse. France blamed Washington for the tragedy and used it to rouse public sentiment against the British.

The incident helped lead to a wider war between Britain and France known here as the French and Indian War and as the Seven Years War in Europe. The conflict eventually drew in Austria, Germany, Prussia, Russia, Spain and Sweden, and the fighting spread to colonial land on three continents.

“At the age of 22, Washington had committed a political misstep of global consequence,” writes Coe. “If the American Revolution had not taken place, Washington would probably be remembered today as the instigator of humanity’s first world war, one that lasted seven years.”

But Washington’s reputation didn’t suffer. He gave his diary of the incident to Dinwiddie, who turned it into a propaganda tool for the British, and continued his professional ascent.

By the time of the American Revolution, Washington had a vast knowledge of the Royal Army, a 6-foot-2 stature that lent him automatic gravitas and, after 13 successful years as a farmer, plenty of wealth. He was also fiercely dedicated to the American cause.

When the time came to choose a leader for the colonial army, no one else was considered, and he was seen as equally deserving to serve as the new country’s first president.

But by the time Washington left office in 1797, the country was bitterly divided over US relationships with warring Britain and France, and most of the Founding Fathers were done with him.

“The President is fortunate to get off just as the bubble is bursting, leaving others to hold the bag,” a resentful Thomas Jefferson complained in a letter sent that year to James Madison. “He will have his usual good fortune of reaping credit from the good arts of others, and leaving them that of his errors.”

James Monroe, who would later become the United States’ fifth president, infuriated Washington in 1797 with a 473-page critique of his administration, including a claim that he used Chief Justice John Jay in various unconstitutional executive-branch roles, such as acting Secretary of State.

Even John Adams, who had once called Washington “an exemplification of the American character,” later changed his tune, writing of his presidency in an 1812 letter that he was “too illiterate, unlearned, unread for his station and reputation.”

Certainly, Washington never earned a reputation as a man who fought for equality. While it is widely believed that he freed his slaves upon his death in 1799, in fact, only one slave, a favorite named William Lee, was let go. The rest, he decreed, would only be freed after the death of his wife, Martha.

But this caused a problem for Martha, as she spent the rest of her life “deathly afraid of his slaves,” who knew that her passing would lead to their freedom.

“She did not feel as tho her life was safe in their hands,” Abigail Adams wrote in a letter to her sister. After a lengthy spell of poor health, Martha Washington succumbed to a high fever and died at age 70 in 1802.