In which areas of the United States was the Ku Klux Klan popular?

Mostly out west

All over the country.

Only in the south.

I think its the south cause remember that's where all lot of Africans where

Mostly, the Ku Klux Klan was most popular on the South, because most African Americans escaped from the plantations in the South, and the Ku Klux Klan was mostly responsible for capturing them, or killing them.