Statistics for occurrence #1 of “Boston harbor” in chapter 13, page 535 of William Schouler, A history of Massachusetts in the Civil War: Volume 2:

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This ancient and historic county is bounded north-east and east by Massachusetts Bay, north by Norfolk county and Boston harbor , north-west by Norfolk county, west by Bristol county, and south-east and south by Buzzard's Bay and Barnstable county. The North River, emptying into Massachusetts Bay, and numerous branches of the ...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Boston Harbor (Massachusetts, United States) 627 10 1 0 0 user votes
Boston Harbor (New Hampshire, United States) 0 0 0 0 0 user votes
Boston Harbor (Washington, United States) 0 0 0 0 0 user votes
Boston Harbor (Washington, United States) 0 0 0 0 0 user votes

† 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.