80901
They departed Fort Leavenworth on May 31 , 1858 and headed west , with Mills producing photographs along the way .
 person: Mills
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: Mills 
Answer:
 person: Mills