Textbooks often say the Panthers were violent and anti-white. For example, the Teacher Curriculum Institute's "History Alive! The United States" reads, "Black Power groups formed that embraced militant strategies and the use of violence. Organizations such as the Black Panthers rejected all things white and talked of building a separate black nation." In reality, the Panthers believed in using violence only in self-defense. This passage also tries to separate the Panthers from "nonviolent" civil rights groups. The Panthers didn't begin out of thin air, however, but developed from their relationships with other civil rights organizations.
Summarize this passage into one sentence.