"i have a dream" speech:
his speech is famous for all the ideas and hopes for the future. His speech was 17 minutes long and many had listened. 

Meeting with Malcolm X:
His one and only meet with Malcolm X, another civil rights leader, only lasted minutes but was a moment in history.

His arrest:
Martin Luther King getting arrested was a huge setback for his actions. He was jailed for  eight days in Birmingham Jail.