Statistics for occurrence #1 of “Billerica” in chapter 1, section c.1.1, page 3 of Medford Historical Society Papers, Volume 7.:

...hese latter, which varied from one to six miles in length, sixteen locks, like huge steps, were built, overcoming a rise of one hundred and four feet from tide water at Charlestown, to the Concord at Billerica , and a descent of twenty-six feet to the Merrimack at Chelmsford. Five others provided entrance into these rivers, and also into the Mystic at Medford, while suitable waste weirs were placed contig...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Billerica (Massachusetts, United States) 452 14 6 0 0 user votes
Billerica (Massachusetts, United States) 4 2 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.