Final answer:
The Black Codes passed by Southern states and the rise to power of former Confederate leaders reinforced Congress' fears of civil rights suppression during Reconstruction.
Explanation:
During Reconstruction, following the Civil War, Southern states passed Black Codes which restricted the rights of Black people, including the right to vote and access to education. This reinforced Congress' fears of civil rights suppression. Additionally, former Confederate leaders came to power in many southern states, further threatening the rights of Black individuals.
Learn more about Civil Rights Suppression during Reconstruction here:
https://brainly.com/question/30749321