What was used to prevent african american men from voting in the late 1800s?

Grandfather clauses, is the right answer.

Explanation:

The grandfather clause in the history of the United States was a provision following which an old law was continued to practice to some existing conditions while a new law will follow in future cases.

In the southern states, throughout the Reconstruction period, this particular clause prohibited the African American community to cast their vote in the elections. This was the time when the southern states implemented heavy tax duties on those who wanted to cast their votes.

c: in the east might be the correct answer