A Thomas Jefferson painting by Charles Wilson Peale in 1791....

A Thomas Jefferson painting by Charles Wilson Peale in 1791. This portrait depicts Jefferson as he looked around the time of his travels to Long Island. Credit: Independence National Historical Park

On June 13, 1791, two future presidents rode across Suffolk County on horseback. Thomas Jefferson, who 15 years earlier wrote the Declaration of Independence, and who nine years later would be elected the third president of the United States, was one of the riders. On this day, he was secretary of state under President George Washington.

His saddle mates included his Virginia neighbor, James Madison, the Father of the Constitution, as he would one day be called, who in 1808 would be elected the fourth president. The two men were the best of friends. Jefferson called Madison “Jemmy.’’

On this day, a third man of distinction rode with them. He was William Floyd, the owner of a large estate near Mastic. With Jefferson, Floyd shared a unique honor -- he, too, had scratched his name with a quill pen on the Declaration of Independence.

It was not necessarily presidential politics that brought them to a patch of woods near Floyd’s estate. Jefferson had traveled to Suffolk County to meet a group of Unkechaug Indians in hopes of finding someone who knew their ancient language. The vocabulary compiled by Jefferson that day would be one of only two ever made of the Algonquian language of the Long Island Indians -- and most of it would be lost to history when a trunk containing his notes was stolen off a boat while it was being shipped back to Monticello, his Virginia estate, at the end of his presidency.

The 271 words that survived are a gift to Long Island, historians say.

“Among Jefferson’s many interests was Indian languages,’’ said Kathleen Bragdon, a linguist at the College of William and Mary, Jefferson’s alma mater. “It may be his least known, but he wanted to collect Algonquian vocabularies from the last speakers.’’

Jefferson found what he was looking for on an anemic stretch of farmland and woods by a salt creek near present day Mastic, where a group of Unkechaugs eked out a meager existence as farmers and fishermen. They lived in shacks along the woodsy fringe of well-tended farms and estates owned by Floyd’s neighbors.

Among the group, Jefferson wrote that he found “but three persons of this tribe now who can speak its language. They are old women.’’ From two of them, Bragdon said, Jefferson compiled a glossary of words, which were similar to vocabularies of Connecticut Indians who spoke an Algonquian language called Quiripi.

A month before they arrived on Long Island, Jefferson wrote to a family member that he and Madison would soon leave on a trip to Lake George, in upstate New York. From there, he wrote, they would cross into Vermont, travel by boat down the Connecticut River to New Haven, and then journey overland to New York and Philadelphia. But in a letter to Madison written the next day, Jefferson proposed a change in the itinerary. When they reached New Haven, he said, they should cross over to Long Island.

The two giants of the young American republic spent the night of June 12 at a Southold inn owned by a Christiana Peck. The next morning, they stopped at another inn, in Riverhead, and from there they rode south and west along well-traveled cart paths to Floyd’s estate and the Indian village where Jefferson met the three women.

“Primarily, I think this trip to New York was more about politics than Indian languages,’’ said Bernard Sheehan, a history professor at the University of Indiana. “After all, both these men would soon run for president. But Jefferson wanted to write down Indian languages because he was interested in their origins. He thought these languages proved that the American continent was older than Asia. He later changed his mind about this.’’

But much of Jefferson’s research would be lost. When his presidency ended in 1809, he packed his belongings -- including 50 Indian vocabularies he had collected over the past 30 years -- into a trunk that was shipped to Virginia on a boat. On the last leg of its journey up the James River, the trunk was stolen and the contents tossed into the river.

In a letter, Jefferson described the loss: “An irreparable misfortune has deprived me of the Indian vocabularies which I had collected. They were packed in a trunk of stationary, and sent round by water with about thirty other packages of my effects, from Washington, and while ascending James River this package, on account of its weight and presumed precious contents, was singled out and stolen.

“The thief, being disappointed on opening it, threw into the river all its contents, of which he thought he could make no use. Among these were the whole of the vocabularies. Some leaves floated ashore and were found in the mud but these were very few, and so defaced by the mud and water that no general use can ever be made of them.’’

The pages found in the mud were restored and ended up in the American Philosophical Society library, in Philadelphia. Copies of the Unkechaug vocabularies were made in the 1920s by Long Island historian Morton Pennypacker, who donated them to the East Hampton Library.

As for Jefferson, he said in a letter a few months after the loss of the Indian vocabularies that he was pleased that the culprit had been caught and put on trial. While the fate of the thief is not known, Jefferson, in that same letter, said he would no doubt be hanged.

Newsday travel writer Scott Vogel took the ferry over to Block Island for a weekend of fun. Credit: Randee Daddona

Updated now Newsday travel writer Scott Vogel took the ferry over to Block Island for a weekend of fun.

Newsday travel writer Scott Vogel took the ferry over to Block Island for a weekend of fun. Credit: Randee Daddona

Updated now Newsday travel writer Scott Vogel took the ferry over to Block Island for a weekend of fun.

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