And rightly so -- King's iconic 1963 speech at the Lincoln Memorial urged America to "make real the promises of democracy," captured both the need for change and the potential for hope in American society... and included the arguably most widely-remembered sentence any speaker ever delivered.
Yet King's total body of work is vastly greater. He wrote five books. He gave as many as 450 speeches a year for a number of years. Many of his speeches -- many of his ideas, his hopes, and his dreams for our country -- don't get the attention they deserve.
Here are two.
"Our God is Marching On."
This speech from March 25, 1965, on the steps of the Alabama state capitol marked the end of the Selma to Montgomery march.
After a four day march from Selma to Montgomery, a city often called "The Cradle of the Confederacy."
"They told us we wouldn't get here. And there were those who said that we would get here only over their dead bodies, but all the world today knows that we are here and we are standing before the forces of power in the state of Alabama saying, 'We ain't gon' let nobody turn us around.'"
In many ways the speech celebrated the end of the first phase of the civil rights movement, seeking political and legal rights. But King quickly shifted the focus to economic equality.
"Like an idea whose time has come, not even the marching of mighty armies can halt us. We are moving to the land of freedom.
How long? Not long, because no lie can live forever.
How long? Not long, because you shall reap what you sow.
How long? Not long, because the arc of the moral universe is long, but it bends toward justice."
King's use of the repetitive phrase, "How long? Not long!" became a powerful rallying cry -- and a symbol of hope.
"A Time to Break the Silence"
This speech from on April 4, 1967 at New York's Riverside Church was arguably his most controversial -- at least when it was first delivered.
At a time when many Americans still supported it, even key members of King's staff recommended that he not deliver this speech in which he came out against Vietnam War.
Afterwards, President Johnson, who had (at least quietly) supported King's civil rights efforts, stopped talking to him. Newspapers told him to "stick to civil rights." Civil rights leaders criticized him. Huge numbers of supporters backed away.
"A nation that continues year after year to spend more money on military defense than on programs of social uplift is approaching spiritual death."
Strong words, certainly, but King's remarks became even more pointed.
"We are taking the black young men who had been crippled by our society and sending them 8,000 miles away to guarantee liberties in Southeast Asia which they had not found in Southwest Georgia and East Harlem. So we have been repeatedly faced with the cruel irony of watching Negro and white boys on TV screens as they kill and die together for a nation that has been unable to seat them together in the same schools."
The Washington Post and the New York Times called the Riverside Church speech a mistake on King's part. Others, like James Bevel, King's partner and strategist in the Civil Rights Movement, called it King's most important speech.
"The war in Vietnam is but a symptom of a far deeper malady within the American spirit," King said. He asked America to "rapidly shift from a 'thing-oriented' society to a 'person-oriented' society. When ... profit motives and property rights are considered more important than people, the giant triplets of racism, materialism, and militarism are incapable of being conquered."
Controversial, maybe... but also incredibly hard to argue against.