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.

In an interview published by NPR’s Book of the Day podcast on Jan. 3, writer Jonathan Eig, who authored the biography 'King: A Life,' said that Dr. Martin Luther King Jr. was "a protest leader who really does not like conflict.

It was first proposed four days after King’s 1968 assassination outside a Memphis motel. It took 15 years until it became a federal holiday.