It started off with anti-immigrant/anti-black/anti -Catholic feelings right after WWI and was heavily active throughout the early 1920's. Yet, after the National Origins Act of 1924 was passed (Which reduced immigration), the membership saw a drop. They lingered around in a much smaller group after that. Now they're just Evangelicals.http://imgur.com/SKILzpF
The KKK was actually most dominant in Indiana in its second wave. The KKK also had a presence in the Michigan town that Malcolm X lived in when he was younger influencing his racial views.