Throughout the early seasons of "Murder, She Wrote," the existence of Joshua Peabody is treated as a local legend, with Seth Hazlitt serving as chief skeptic. In this episode, Joshua Peabody is treated as a recognized local figure with living descendants and Seth Hazlitt no longer seems to question whether he really existed.
Immediately upon seeing an apparently old document, and especially on reading the date, Jessica would have handled it much more delicately.