Final answer:
Malcolm X was known as "the angriest black man in America" and believed in the right to self-defense, contrasting with MLK's nonviolent resistance. He was a member of the Nation of Islam but later evolved his views after a pilgrimage to Mecca. Malcolm X laid the groundwork for the Black Power movement and upheld the use of violence in self-defense against racial oppression.
Step-by-step explanation:
The individual who called themselves "the angriest black man in America" and believed in the right to self-defense as opposed to the nonviolent approaches of Martin Luther King Jr. was Malcolm X. Malcolm X was a key figure in the civil rights movement who, after joining the Nation of Islam, became a prominent advocate for the rights of African Americans to defend themselves against racial violence and oppression. He differed from MLK's philosophy by endorsing the idea that violence was an appropriate response to violence enacted against African Americans. Malcolm X's tenure in the Nation of Islam drastically shaped his views on racial separation, self-defense, and Black empowerment. However, after his pilgrimage to Mecca, his views regarding Black-White relations evolved, becoming more inclusive before his assassination in 1965.
Malcolm X was instrumental in laying the foundation for the Black Power movement, and many young African Americans found his messages especially resonant after the assassination of Martin Luther King Jr. One notable aspect of his legacy is that he provided an intellectual basis for Black Nationalism and the legitimacy of using violence for self-defense.