His105 discussion week 7

The 15th Amendment to the Constitution guaranteed the right to vote for all citizens regardless of “race, color, or previous condition of servitude.” If the 15th Amendment already guaranteed the right to vote for all races, why did Congress pass the Voting Rights Act? Why didn’t the government just enforce the 15th Amendment?
Why did Martin Luther King promote non-violence? How was his policy of non-violence effective?

At keast 125 worlds each question