Statistics for occurrence #1 of “Merrimack River” in chapter 1 of Medford Historical Society Papers, Volume 7.:

... the French War, and whose diary is replete with interest, seems to have labored under a disadvantage, but his work led up to a complete survey by an expert survey, Samuel Weston. He found that the Merrimack River at Chelmsford was lower than the highest point the canal would traverse, instead of higher, as was at first supposed; so that other water than that of the Merrimack must fill the canal in its course ...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.