This plaque is located in Dover, NH at the (approximate) intersection of Littleworth Rd and Industrial Park Drive. While I originally read about it here and here, it’s located about five miles from where I live.
The inscription reads: “John Hayes (see John Hayes of Dover, New Hampshire), The Scotsman, came to Dover about 1680, married Mary Horne, and established a family on the surrounding acres. Their integrity and industry are held in memory by their descendants. 1934″