Martin Luther King Jr. Day is centered around the Civil Rights leader’s January 15 birthday and was signed into law by President Ronald Reagan in 1983. Though there are many reasons for celebrating and debating his life’s legacy, Martin King Jr. is primarily remembered in the 21st century for his famous “I Have a Dream” speech.

Though King had socialist leanings, he wisely avoided economic or purely political arguments in his famous 1963 oration and drew upon the intellectual tradition of the Founding Fathers and Abraham Lincoln to make his case for racial equality. King made obvious references to the Declaration of Independence and Gettysburg Address, saying in front of Washington D.C.’s Lincoln Memorial, “Five score years ago, a great American, in whose symbolic shadow we stand today, signed the Emancipation Proclamation. This momentous decree came as a great beacon light of hope to millions of Negro slaves who had been seared in the flames of withering injustice. It came as a joyous daybreak to end the long night of captivity.”

King explained how equality before the law that Lincoln and the United States stood for had not been accomplished, that a century after the Emancipation Proclamation it was time to fulfill the promise of liberty and equal rights for all Americans.

“In a sense we’ve come to our nation’s Capital to cash a check. When the architects of our republic wrote the magnificent words of the Constitution and the Declaration of Independence, they were signing a promissory note to which every American was to fall heir,” King said. “…I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character.”

By framing his argument in the natural rights tradition of the United States—and placing it within the context of the long history of American ideas—King was able to reach many who might not be initially amenable to his views. In many ways this was a rebuke to the idea that the American republic was originally founded on racist premises and prejudice.

Historian and political philosopher Harry Jaffa wrote in his book The Crisis of the House Divided how the conception of the racist founding reached its crescendo in the 1968 Commission on Crime and Civil Disorder when blame for urban rioting was “placed upon white racism, and the endemic character of that racism was held to be exhibited above all in the fact that the Declaration of Independence had failed to include within its scope members of the Negro race! Taney’s opinion in Dred Scott—that the Founders believed that Negroes had no rights which white men were bound to respect—had now become the hallmark of official liberalism.”

But as King, Lincoln, and Jaffa argued, the Declaration’s statement that “all men are created equal” really did mean all men regardless of race—that racial equality before the law was a continuity with the American philosophical tradition, not a break from it.

Jaffa wrote in the essay “Calhoun versus Madison:The Transformation of the Thought of the Founding A Bicentennial Cerebration”:

When Martin Luther King, Jr., made his famous speech on the steps of the Lincoln Memorial, he dreamed of a day when race, color, creed, and ethnicity would be transcended. He dreamed of a day when human beings–that is to say, individual men and women– would be judged by their character and accomplishments, not by the color of their skin–or by any other irrelevant characteristic. He dreamed of a day when the principles of the Declaration of Independence would be fully realized, not only in the institutions of American government, but in the spirit of American society.

Peter C. Myers wrote in a Heritage Foundation report, “Martin Luther King, Jr., and the American Dream” that the I Have a Dream speech is virtually “unrivalled among 20th-century American speeches.” King has become an icon for mainstream America even as “divisions among the broad class of King’s admirers persist and even intensify.”

Myers concluded:

At the level of first principles—in his commitments to natural rights, democratic government, and the irrelevance of race to moral personhood and just social deserts—King’s political thought might properly claim a consensus among virtually all American citizens. With respect to the relation between those first principles and the programmatic means for effecting them, however, his thought leaves much ground for legitimate dispute.

This is Martin Luther King Jr.’s legacy. As Breitbart News’ Jerome Hudson recently said on American race relations and the difference between now and King’s era, “We have not reached the mountaintop, but for all intents and purposes, we certainly are closer. We’ve come a long way as viewing one another, whether we look different or not, as equal, as [Thomas] Jefferson would want us to.”