Why was it difficult for free african americans to find a safe place to live

What would lead a historian to consider two events to have a relationship of correlation rather than causation

Political rights for women grew most rapidly on the western frontier primarily because (1) the settlers were influenced by native american indian societies (2) women greatly outnumbered men in the west (3) pioneer life often required men and women to share responsibilities equally (4) immigrants settling in the west brought ideals of gender equality from europe

Under the new imperialism europe did not need large numbers of people to control territories because of