How did members of the KKK try to intimidate African-Americans?
They used violence to make African-Americans afraid of them. People would be dragged from their homes and beaten, or even hanged. Homes, businesses, and churches were burned or vandalized. Or they could use the threat of violence: a wooden cross would be erected near someone's home and set afire, to warn them not to do anything against the Klan or its beliefs.
The Klan members wore hoods or masks so that they could not be identified, and most of their cowardly acts took place under the cover of night.