Answer:
Granger didn't believe that black people should own land, as they were not considered people at the time. He consistently threatened to take their land if they could not pay for it.
Step-by-step explanation:
Sorry, I'm just copying this from my comment. :)
Granger was the richest man in the area, and he had many tenant farmers that begged to farm on his land. The Logan land would have been valuable to him, so he wanted it.