One day in 1815 Captain Joseph Merrick of Pittsfield, Massachusets plowed his field on his farm, built on what had been called "Indian Hill" in the 18th century (later a fort was established there in 1754, and so in his time it was called "Fort Hill."
In turning up the earth out popped tefillin--which is what it proved to be, although he didn't know it. A local resident named Elkanah Watson (note the last name; don't be fooled by the first) heard about it and went to investigate. At Merrick's house he found several Christian clergymen, all of whom were excited, realizing it must have belonged to a Jew. This Watson knew of the theory that the Native American Indians were descended from the ten lost tribes of Israel, and was excited.
What is interesting is that he claimed to compare "this phylactery with those described in the Old Testament." I'd like to know where! In any case, he wrote that they "are described in Scripture as composed of five folds of raw hide or leather, sewed completely together by the entrails of animals. In order to understand the appearance of this discovery, imagine five pieces of leather or raw hide, or some composition similar to India rubber, and capable of resisting the ravages of time and exposure, cut into squares of two inches, sewed together with entrails. Suppose, also a hole in the center, half an inch in diameter made to admit a tube two and a half inches long with eyelet holes at the corners to receive strings--and you will have an idea of this article."
In any event, Watson described the difficulty of opening it and how he "drew out from the tube three of four scrolls of parchment, which it contained when found, and inscribed with texts of Scripture, written in beautiful Hebrew in an elegant manner, and the ink of a beautiful jet black. The parchment, writing, ink, were all perfectly fresh."
Locals declared that it belonged to early Jewish settlers in Pittsfield, perhaps one from Germany who was remembered, who had since gone.
On the other hand, some investigators wished that it were Indian, and so declared that it was (the hill happened also to be an Indian burial ground).
Lee M. Friedman, whose article "The Phylacteries Found at Pittsfield, Mass," PAJHS, 1917, 25, pp. 81-85 is where this info comes from, noted that upon investigation an Isaac Isaacs appeared on the Pittsfield military rolls of 1780-1781. However, he sees no evidence that this person was Jewish and in fact might have belonged to the non-Jewish Isaacs of Connecticut.
On the other hand, five separate men called Isaac Isaacs show up in the 18th century in A Biographical Dictionary of Early American Jews by Joseph R. Rosenbloom. However, they are all in New York City or Long Island, and even if one of them is also Isaac Isaacs in the army in Pittsfield, we still haven't even come close to showing that the tefillin were his.