Why Did Blacks Initially Settle in the Harlem Area of New

Why did blacks initially settle in the Harlem area of New York City?

A) The area had been a way station on the underground railroad and had a history of black protest.
B) Because builders were unable to sell to whites, they sold to blacks to avoid bankruptcy.
C) Blacks were forced into the area by whites who wanted them removed from more expensive areas.
D) For almost a century, numerous powerful black politicians resided in the area.