It was not only the violence and intimidation of Blacks.
The KKK were/are politically active against Catholics and Jews,
and essentially anyone else that was not white and Protestant.
Oregon has a significant legal and social history with the KKK.
Essentially, the basis for
private schools in the US was established
by the
US Supreme Court in ruling in 1925 against the KKK
and in favor of St Mary's Academy here in Portland, OR.