15841
History Precursor to Denver Tramway In 1867 the Denver Horse Railroad Company was incorporated and given " a period of thirty five years the sole and exclusive right and privilege of constructing a horse railroad in the city of Denver and the additions thereto . "
 Denver, Denver, Denver
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Denver, Denver, Denver