63881
It developed a deserved reputation as one of the least healthy locations in British North America for whites , although mistaken observations over the period led some doctors to think that blacks had a natural immunity to the disease .
 British North America
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 British North America