Final answer:
Terrorism and intimidation were used to deny blacks the freedoms promised by the 13th, 14th and 15th Amendments, with the Ku Klux Klan and other groups using violence and tactics such as lynching to intimidate them.
Step-by-step explanation:
Terrorism and intimidation were used to deny blacks the freedoms promised by the 13th, 14th and 15th Amendments in the United States. Despite the ratification of these amendments, African Americans faced widespread violence, discrimination, and voter suppression. The Ku Klux Klan and other terrorist groups used various methods to intimidate black people and their white sympathizers, such as lynching, vigilante executions, and violent attacks. These acts of terrorism aimed to maintain white supremacy and deny African Americans their rights and freedoms.