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The eastern boundary of the Louisiana purchase was the Mississippi River , from its source to the 31st parallel , though the source of the Mississippi was , at the time , unknown .
 location: Louisiana; location: Mississippi River; location: Mississippi
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Louisiana, Mississippi River, Mississippi 
Answer:
 location: Louisiana; location: Mississippi River; location: Mississippi