Question

What happened on th 15th amendment?

Answer 1

Here's something that might help you out:
http://kids.laws.com/15th-amendment

Answer 2

The Fifteenth Amendment (Amendment XV) to the United States Constitution prohibits each government in the United States from denying a citizen the right to vote based on that citizen's "race, color, or previous condition of servitude" (for example, slavery). It was ratified on February 3, 1870