NEW YORK, NY.- For years, there had been skepticism about the large portrait of George Washington that has long hung in the baronial Paris residence of the U.S. ambassador to France.

It had been left to the government in 1989 by an American arts patron and was described as a painting by Charles Willson Peale, the celebrated patriarch of America’s first artistic dynasty and founder of the nation’s first public museum.

The near life-size image of Washington — cast as a Revolutionary War hero after the Battle of Princeton, a blue sash adorning his chest — certainly resembled other Peale portraits.

But the painting’s provenance was murky.

Washington’s face was overpainted and “mushy looking,” one Peale expert thought.

Sotheby’s had evaluated the painting for the State Department in 2000 and would refer to it only as “attributed” to Peale.

“It didn’t look like any other portraits in the series,” said Lauren Hall, a conservator with the agency’s Office of Cultural Heritage who was put in charge of authenticating it.

But now, after rigorous analysis including lengthy scientific study of the paint materials and historical documents, experts are confident they can declare the portrait a true Peale, one of many versions of his 1779 original, which the artist painted over and over in an era when copiers did not exist and an image of Washington was thought essential to the new nation’s glorification of its sovereignty.

This portrait had been en route to the Netherlands in 1780, an intended diplomatic gift for its leadership, when the ship carrying it was captured by the British navy. By this time, Peale, who served in combat with the Pennsylvania militia, had already painted Washington from life in 1772, 1776 and 1777. He would do so again in 1783, 1787 and, finally, in 1795, when Washington was president, for a record seven original portraits from life.

Experts say it is not known how many times Peale reproduced his original 1779 image of Washington at Princeton, now at the Pennsylvania Academy of the Fine Arts in Philadelphia. But in addition to a handful of close copies, including the Paris version, there are many variations.

The expert findings, which were announced in time for Presidents Day and are detailed in a video, are the product of an inquiry that began in 2016, decades after the painting had been given to the U.S. government by Caroline Ryan Foulke. She was the granddaughter of Thomas Fortune Ryan, the tobacco magnate and financier who became one of the world’s richest men in part by consolidating the New York trolley-car system. She had bought it in the late 1950s or early ’60s from a New York gallery.

The U.S. Embassy in Paris, thinking the portrait was in need of conservation, ended up enlisting Hall, at what was then the State Department’s newly created cultural heritage office. Hall, initially puzzled by the work’s scant documentation, called in two experts. One was Carol Eaton Soltis, a curator at the Philadelphia Museum of Art and author of “The Art of the Peales” (Yale University Press, 2017). The other was Emily MacDonald-Korth, an art conservator and forensic specialist with her own laboratory, Longevity Art Preservation in Miami.

Their research was initially hobbled by the pandemic and other factors, but last spring, MacDonald-Korth used high-tech equipment to study the underpainting and trace the elements of the paints used in the original in Philadelphia. The experts also analyzed similar Peale portraits of Washington that hang at Mount Vernon in Virginia and in the Senate.

Hall, meanwhile, whose work involves visiting embassies abroad, took photos of the Paris painting for the experts she had hired. Soltis, who had reviewed many a Peale painting, was shocked.

“What am I looking at?” she remembered thinking. “This horrible masklike face.” Peale’s faces, she said, were usually delicate and linear.

MacDonald-Korth figured the heavily overpainted face was a restoration, as often happens before a work changes hands. But she also was concerned about its authenticity.

Several months later, during a visit to London, Soltis called in a favor from an art dealer she knew who got her into the closed library of the National Portrait Gallery. There she found an auction catalog that confirmed the painting had been sold by Sotheby’s in 1946 to the London office of Knoedler & Co.

Further analysis revealed poke marks in the painting, some of which appeared to have been painted over around the face. MacDonald-Korth said she thought there were too many to think they had happened by accident.

It made sense to the experts. Here was an image of a military hero that had been seized by British forces and ended up in the country he defeated.

“It could have been damaged on purpose,” MacDonald-Korth said, perhaps immediately after its seizure. It was impossible to say for sure, the experts said. In 1781, an unknown vandal had also damaged Peale’s original of Washington at Princeton.

Wendy Bellion, a professor of American art history at the University of Delaware and author of “Iconoclasm in New York,” about attacks on British monuments during the American Revolution, said it is often difficult to say who vandalized artworks. For example, she said, little is known about the identity of the mob that tore down King George III’s statue on Bowling Green in lower Manhattan, New York, in 1776 — an act that Washington distanced himself from.

Actually, after the war, Bellion said, Washington became quite popular in England — “a rock star,” she said, among his former wartime adversaries, including King George.

The forensic analysis of the painting finally took Soltis and MacDonald-Korth to Paris, where, with help from specialists at the Louvre, they determined that, aside from the overpainting, the brush strokes and the character of the paint used were in line with works already embraced as by Peale.

The origin story of the painting, some of which was known but had large gaps, also came together through their research, the experts said.

The original portrait had been commissioned by Pennsylvania’s Supreme Executive Council so that, in the words of the council, “the contemplation of it may excite others to tread in the same glorious and disinterested steps which lead to public happiness and private honor.”

Anna O. Marley, chief of curatorial affairs at the Pennsylvania Academy of the Fine Arts, said Washington sat for the portrait at Valley Forge, Pennsylvania; New Brunswick, New Jersey; and Philadelphia, where Peale — who fought at Princeton and had gone back to view it — painted the battle site as the backdrop with the college in the distance.

The painting was an immediate hit. Peale was besieged for copies. One was ordered by Henry Laurens, a founding father, wealthy merchant and slave trader from South Carolina. In 1780, Laurens was carrying the painting to the Netherlands to negotiate a $100,000 loan for the U.S. forces when his ship, the Mercury, was captured off Newfoundland by a 28-gun frigate of the Royal Navy, the Vestal, commanded by Capt. George Keppel.

Laurens ended up imprisoned for a year in the Tower of London. Keppel handed over the painting as a prize of war to his Albemarle family, where it would remain for the next 166 years.

But the linear trail of its history became confused when the Albemarles commissioned an artist to create a copy of the painting around 1918, nearly a century after Peale’s death. The copy, by an accomplished British artist, William Alan Menzies, came to hang in the British prime minister’s offices and residence at 10 Downing St.

A few years later, in a show of Washington portraits in New York at the Colony Club, an exclusive women’s retreat, the painting captured at sea was mistakenly described as hanging in the meeting room of the British Cabinet as a gift of the Albemarles to the British nation. The designation clouded the provenance of the real painting, which had never left the Albemarle family.

The family later consigned the real portrait for the 1946 auction, where it was bought by Knoedler. It was sold later that year to E. Jay Rousuck of the Scott & Fowles Gallery in New York.

Rousuck, an authority on sporting paintings, was a co-founder of the National Museum of Racing in Saratoga, New York, and in 1953, he put the portrait on display in his museum, seemingly as much for the horse in the background as for Washington.

Sometime in the next few years, according to Soltis’ research, it was purchased by Caroline Foulke, who lent it to the Paris ambassador’s residence in 1981. After she died in 1987, it was bequeathed to the government under the terms of her will.

The government has not set a value on the painting, which typically hangs in the Louis XVI salon at the residence, now occupied by Ambassador Denise Campbell Bauer. When it was appraised by Sotheby’s in 2000 — and still not fully embraced as a Peale — the auction house estimated its value at $1.2 million. Another of the few close copies was sold at auction in New York in 2006 to a private American collector for $21.3 million, which Christie’s then called a record for an American portrait.

For now, the painting is headed for the additional conservation work that originally set in motion the full investigation into its provenance. That work will include an effort to safely dissolve, if possible, the later overpainting of the face, and will probably be done in France, MacDonald-Korth said.

“I wouldn’t recommend crossing the Atlantic again,” she said.

This article originally appeared in The New York Times.