The author of the book 'Stride Toward Freedom' is Martin Luther KING Jr., whose initials are MLK, which can be abbreviated to the 4-letter word KING. Martin Luther KING Jr. was an American Baptist minister and civil rights activist who became the most visible spokesperson and leader in the civil rights movement from 1955 until his assassination in 1968. He is best known for his role in the advancement of civil rights using nonviolent civil disobedience based on his Christian beliefs.