 He was confirmed by his fellow Senators before the full KKK connection was known; Justice Black said he left the Klan when he became a senator.Many groups and leaders, including prominent Protestant ministers such as Reinhold Niebuhr in Detroit, spoke out against the Klan, gaining national attention.The Jewish Anti-Defamation League was formed in the early 20th century in response to attacks on Jewish Americans, including the lynching of Leo Frank in Atlanta, and the Klan's campaign to prohibit private schools (which was chiefly aimed at Catholic parochial schools).