Statistics for occurrence #1 of “Montana” in entry idaho of Harper's Encyclopedia of United States History:

...sent northern boundary. By act of Congress of March 3, 1863, the Territory of Idaho was created from a portion of Oregon Territory, with an area which included the whole of the present State of Montana and nearly all of that of Wyoming. In 1864 the Territory lost a part of its area to form the Territory of Montana, and in 1868 another large portion was cut from it to form the Territory of Wyoming...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Montana (Montana, United States) 252 186 0 0 0 user votes
Montana (Arkansas, United States) 0 0 0 0 0 user votes
Montana (Bulgaria) 0 0 0 0 0 user votes
Montana (Kansas, United States) 0 0 0 0 0 user votes
Montana (New Jersey, United States) 0 0 0 0 0 user votes
Montana (Ohio, United States) 0 0 0 0 0 user votes
Montana (Switzerland) 0 0 0 0 0 user votes
Montana (West Virginia, United States) 0 0 0 0 0 user votes
Montana (Wisconsin, 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.