Mr. Martin Luther King Jr. was a social activist and baptist minister who played a key role in the Americans civil rights movement from the mid 1950s until his assassination in 1968.
The passage that brought him to lead a protest in Birmingham according the his letter from the jail: "There are just laws and there are unjust laws I would agree with St. Augustine that an unjust law is not a law at all" and he cited to Mr. Thomas Aquinas an unjust law is a human law that is not rooted in eternal and natural law.