Historians use diaries and personal letters to help them understand the past, like events during the Civil Rights Movement. While in a jail in Birmingham, Alabama, in 1963, Dr. Martin Luther King, Jr. wrote a letter to a group of religious leaders who were concerned about his actions. How would reading this letter help historians better understand the Civil Rights Movement? Choose the best answer

1. It describes jail life in the 1960s.
2. It shows Dr. King’s level of education.
3. It demonstrates how people wrote letters in the 1960s.
4. It explains why Dr. King participated in nonviolent protests.