On Friday, I heard a story on Radio Boston about the Boston accent in which one of the linguists claimed that Massachusetts residents didn't start dropping their rs until the nineteenth century. That didn't make a whole lot of sense to me, especially since the other linguist noted that the Boston accent is a descendant of the English accents brought over by the 17th-century settlers.
A later date for dropped rs does not fit with the evidence I've been finding on my gravestones. The New England carvers have quite a problem with the word "departed," which is remarkable when you consider that it appears on at least a third of the 18th-century stones.
I found two more "depated" stones today. This brings my total up to six (more here and here).
The Abraham Gibson stone in Stow, MA dates from 1740:
The Francis Brown stone (1800) is in Lexington, MA: