On January 21, we celebrate Martin Luther King Jr. Day. By remembering King, we remember what we stand for as a nation: the equal protection of the rights of all. King reminded us that the government of all should be partial to none.

And no reminder of King’s has stood the test of time better than his "I Have a Dream" speech before the Lincoln Memorial. On August 28, 1963, a quarter million people came to Washington, D.C. to hear a 33-year-old black preacher talk about America. It has become perhaps the most famous speech delivered by an American in the modern era.

The American people had come to know Martin Luther King Jr. as the head of the Montgomery Improvement Association, which led a successful bus boycott to desegregate public transportation, and as director of the Southern Christian Leadership Conference, which organized non-violent protests throughout the segregated South.

In speeches, sermons, and writings, King appealed to the principles of the Declaration of Independence and U.S. Constitution, as well as the nation’s Judeo-Christian heritage, as a reminder of what Americans promised themselves as a self-governing people. What makes King’s dream all the more remarkable—his appeal to the nation to "rise up and live out the true meaning of its creed"—is his own experience with racial discrimination.

On "Good Friday," April 12, 1963, King was thrown into solitary confinement in the Birmingham City jail for picketing. Earlier in the Civil Rights Movement, he received death threats, his home was bombed, and he was stabbed with a penknife that grazed his heart. In spite of all this, he delivered a triumphant speech at the nation’s capital, expressing his hope that America would mend her ways and do justice to her "citizens of color."

King had faith—a Christian faith, an American faith—that white Americans would no longer reserve the protections of government for themselves. He believed they had it in their hearts to extend government’s protective reach to all citizens regardless of race. His faith proved to be well founded, though an assassin’s bullet, on April 4, 1968, kept him from seeing the full harvest of the Movement’s labors.

True to his calling as a minister, King preached to a national choir that had forgotten its verses. Whether in his letter from a Birmingham jail or his speech before the Lincoln Memorial, King challenged Americans to live up to their professed ideals. And they responded by passing the 1964 Civil Rights Act and 1965 Voting Rights Act.

To be sure, King’s legacy is not unmixed. In his later years, he abandoned the language of "citizenship rights" and endorsed the rhetoric of entitlements. This gave legitimacy to Great Society programs that proved neither great nor conducive of a society in which anyone would choose to live.

But in remembering King at his best, we remember America at her best. Sharing a dream "deeply rooted in the American dream," King taught us the true meaning of our national motto—E pluribus unum ("Out of many, one"). It was a vision of "the beloved community," where "black men and white men, Jews and Gentiles, Protestants and Catholics" would find that freedom for one’s neighbor entailed freedom for oneself.

Lucas E. Morel is assistant professor of politics at Washington and Lee University in Lexington, Virginia and is an adjunct fellow at the Ashbrook Center.