A Life,' spoke on a Jan. 3 episode of NPR’s 'Book of the Day' podcast about Martin Luther King Jr., and noted that MLK didn’t have plans to become a civil rights leader when he joined the Montgomery Bus boycott in 1965.

King in those last days of his life was speaking to how the environment and the conditions in which people live and work affect their lives and well-being.

Between 1957 and his assassination on April 4, 1968, at age 39, Martin Luther King Jr. gave 2,500 speeches, wrote sermons and homilies and published five books. Meanwhile, the number of books written about King surely number in the thousands.