Statistics for occurrence #1 of “Portsmouth” in chapter 7 of George Bancroft, History of the United States from the Discovery of the American Continent, Vol. 2, 17th edition.:

...as made to do service, when Shaftesbury, proceeding to Westminster, represented to the grand jury the mighty dangers from Popery, indicted the duke of York as a recusant, and reported the duchess of Portsmouth , the kings new mistress, as a common neusance. The extreme agitation was successful; and in two successive parliaments, in each of which men who were at heart dissenters had the majority, the bill f...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Portsmouth (United Kingdom) 107 4 13 0 0 user votes
Portsmouth (New Hampshire, United States) 470 2 134 0 0 user votes
Portsmouth (Dominica) 0 0 0 0 0 user votes
Portsmouth (Iowa, United States) 0 0 0 0 0 user votes
Portsmouth (Kentucky, United States) 0 0 0 0 0 user votes
Portsmouth (Virginia, 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.