Answer: C.
Step-by-step explanation:
The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of race, color, or previous condition of servitude.
Yet states still found ways to circumvent the Constitution and prevent blacks from voting. Poll taxes, literacy tests, fraud and intimidation all turned African Americans away from the polls. Until the Supreme Court struck it down in 1915, many states used the "grandfather clause " to keep descendants of slaves out of elections. The clause said you could not vote unless your grandfather had voted -- an impossibility for most people whose ancestors were slaves.
This unfair treatment was debated on the street, in the Congress and in the press. A full fifty years after the Fifteenth Amendment passed, black Americans still found it difficult to vote, especially in the South." What a Colored Man Should Do to Vote", lists many of the barriers African American voters faced.