Statistics for occurrence #1 of “South Dakota” in entry united-states-of-america-south-dakota-state-of of Harper's Encyclopedia of United States History:

... South Dakota
One of the United States, was formed by the division of Dakota Territory into two States in 1889. It is bounded on the north ...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
South Dakota (South Dakota, United States) 435 247 1 1 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.