Everyone is familiar (I hope) with his "I Have a Dream" speech, given on August 28, 1963 during the March on Washington. It dealt with civil rights in this country and was a milestone in the progress towards equality in America.
Here's the video:
But I started this thread in order to post another speech given by Dr. King on April 30, 1967 at the Ebenezer Baptist Church.
It is his greatest speech, IMO.
It is a speech worth listening to, IMO.
Courage comes in many forms; this speech is one them.