KATONAH, N.Y. (AP) — The inner circle of founders has been set for as long as anyone can remember — Washington, Jefferson, Adams, Franklin, Hamilton and Madison.

Almost never mentioned is John Jay.

"Most people know something about him. ... But very few know the full breadth of his accomplishments. Most are very surprised by what they learn," explains Heather Iannucci, director of the John Jay Homestead in this Hudson River town, where the July Fourth celebration will include a reading of the Declaration of Independence, music and tours of the stately, shingled house where the country's first chief justice lived his final years.

As more of his papers have become available in the past decade, Jay's admirers, ranging from specialists to such popular historians as Joseph Ellis and Walter Isaacson, have been arguing that a founder they believe underrated deserves a closer look — for achievements that extend to virtually every branch of government, on the state, federal and international level.

Jay was one of three contributors to the Federalist Papers, which helped define American government. He was president of the wartime Continental Congress, then served as secretary of foreign affairs, precursor to secretary of state, after the Revolutionary War ended. He was an essential diplomat whose peace negotiations with England, leading to the Treaty of Paris, vastly expanded U.S. territory.

For his accomplishments heading a network of informants during the revolution, actions that helped inspire James Fenimore Cooper's novel "The Spy," the CIA's website calls Jay"the first national-level American counterintelligence chief." He also helped write the New York Constitution, was a founder of the New York Manumission Society and as governor signed legislation that phased out slavery in the state. (Jay himself owned slaves.)

The founders bickered colorfully among themselves, but they agreed on the virtues of Jay. Noting his centrality in the talks with England, John Adams praised him as "of more importance than any of the rest of us." Alexander Hamilton turned to Jay first when conceiving the Federalist Papers, and George Washington thought so much of him that when he was forming his original Cabinet, he offered the first position — any position — toJay, who chose the Supreme Court.

"He's been hiding in plain sight for all this time," says Ellis, the Pulitzer Prize-winning historian who features Jay in his current best-seller, "The Quartet," in which he places Jayamong four founders who made the U.S. Constitution possible. "We can argue about who can be on top of the list of most important founders until the cows come home, but it's clear he should be part of the list."

Jay was a leading nationalist, eager to unify the former colonies, but he has become a regional hero. The John Jay College of Criminal Justice is based in Manhattan. Some students at his alma mater, Columbia University (then King's College), live in John JayHall, and various prizes are handed out by Columbia at the annual John Jay Awards dinner. Some visitors to the homestead arrive from the nearby John Jay High School.

But recognition doesn't approach that of Washington and other peers. Few Jay biographies have been published, and none close to the prominence of Ron Chernow's Hamilton and Washington books or David McCullough's "John Adams." The Library of America has issued editions of the writings of several founders but has no plans for a dedicated book on Jay. In 2005, Walter Stahr's "John Jay: Founding Father" received praise from Chernow and Isaacson among others, but he struggled to find a publisher and ended up with the London-based Hambledon Continuum.

"I signed with a British publisher, for a book about a major founding American father," Stahr wryly observed.

Ellis acknowledged his own slighting of Jay. In his Pulitzer-winning "Founding Brothers," a million-seller published in 2000, Ellis does not include Jay among the eight "most prominent political leaders in the early republic," an omission Stahr points out in his biography. "If I knew what I know now when I wrote 'Founding Brothers,' Jay would have been one of the players," Ellis now says.

Jay supporters believe his relative anonymity is mostly a story of paperwork and personality.

The balding, gray-eyed Jay lived quietly and died quietly, not on a battlefield or in a duel with Aaron Burr, but in his library, at age 83. He was not a humorist like Franklin, or intemperate like Hamilton, but dependable and unusually honorable.

Historian Gordon Wood pointed out that when Jay was New York's governor, he refused to endorse Hamilton's scheme in 1800 to manipulate the state's electoral laws during a close presidential campaign and deny the White House to Jefferson, their political rival. That wasJay's "finest moment," Wood told The Associated Press in an email.

In Stacy Schiff's biography of Franklin in Paris, "The Great Improvisation," she noted thatJay never tried to compete with or undermine Franklin while both were diplomats abroad and was willing to endure financial and physical hardship on behalf of independence. That included spending "30 murderous months on the periphery of the Spanish court," waiting in vain for $5 million in promised aid, Schiff wrote in an email.

Jay, she said, "never seems to lose his cool, or his dignity."

The scarcity of documents has plagued Jay historians. Over the past 60 years, the papers of Washington, Jefferson and others have been duly compiled and made widely available.Jay's papers have been long delayed, with Stahr and others blaming the late Columbia University professor Richard Morris, who for decades had control of the material.

"When Lynne Cheney decided she was going to tackle James Madison, she had a tremendous amount of stuff to work with," says Stahr, referring to Cheney's Madison biography that came out in 2014. "When I tackled John Jay, it was hard."

Morris died in 1989, with only two of four planned Jay volumes completed, and for years the project was idle. New funding revived it in 2004, around the time Stahr was finishing his book. And a team of editors at Columbia led by Elizabeth M. Nuxoll is scheduled to have a seven-volume set completed and released by 2020. The fourth volume is out in November.

Ellis, who drew extensively on Jay's papers for his current book, believes they will establish him not only as a statesman but also as a prose stylist. The letters between Jay and his wife, Sarah Livingston Jay, rank closely with the correspondence of John and Abigail Adams, Ellis says, likening the Jays to the acknowledged first couple among the founders.

"There's a level of candor and intimacy and sharing of private thoughts that most 18th-century marriages didn't have," Ellis says of the Jays.

A merchant's son, John Jay was born in New York in 1745 and grew up comfortably on an estate in Rye, about 25 miles north of the city. He had planned a career in law and, like Franklin, was a moderate in the early years of the revolution, believing that differences with the British could be negotiated. The British use of military power to enforce order changed his mind.

Luck, timing and politics may have harmed his legacy. He was in New York at the time the Declaration of Independence was signed in Philadelphia, and Stahr said it was unclear whether he would have endorsed the document or was still hesitating to break with England. He wrote only five of the 85 Federalist Papers essays, published in 1787-88, because he fell ill.

His greatest controversy involves a document that bears his name. In 1794, more than a decade after the Treaty of Paris, then-Chief Justice Jay was asked by Washington to return to London and prevent what the president and others feared was imminent war. The final agreement, the Jay Treaty, maintained peace but was criticized for being too favorable to the British. Jay, already suspected as pro-British by the rival Republican Party, was burned in effigy in several cities. Scholars still debate whether Jay got the best terms possible.

From the mid-1770s to the early 1800s, he was rarely out of public life and could have stayed longer. Late in John Adams' administration, which ended in 1801, he wanted Jay to return as U.S. chief justice. Jay, who had left that position in 1795 to become New York's governor, declined, and the job went to the man who shaped the modern court, JohnMarshall.

Like a proper gentleman of his time, Jay settled peacefully in the country, having long dreamed of retirement with Sarah. In an early letter to his wife, dated July 21, 1776, when his work on behalf of independence had kept them apart, he expressed "a kind of Confidence or Pre Sentiment that we shall yet enjoy many good Days together, and I indulge myself in imaginary Scenes of Happiness which I expect in a few Years to be realized.

"If it be a Delusion, it is a pleasing one, and therefore I embrace it," he added. "Should it like a Bubble vanish into Air, Resignation will blunt the Edge of Disappointment, and a firm Persuasion of after Bliss give me Consolation."

But Sarah fell ill and died, in 1802, within months of their move. Devastated at first but sustained by his religion, Jay looked after his farm, advocated for education for blacks and became president of the American Bible Society. As his health faded, he asked that instead of a high-priced funeral his family find "one poor widow or orphan" and donate $200. Jaydied on May 16, 1829.

"Unlike John Adams, who spent a lot of time defending his place in history, Jay does not spend a lot of time on that," Stahr says. "He answers letters as they arrive, but doesn't seek out writing engagements. The War of 1812 (between the U.S. and Britain) is very worrisome because he devoted a lot of his time to avoiding that. And he worried about the emerging tensions between North and South.

"In the end, he's more worried about America than he is about John Jay."