Today is a big step in our march toward equality. Gay and lesbian couples now have the right to marry, just like anyone else. #LoveWins. - Barack Obama

But he understood from hard-earned experience that true security comes through making peace with your neighbors.

We will defend our people and uphold our values through strength of arms and rule of law. We will show the courage to try and resolve our differences with other nations peacefully –- not because we are naïve about the dangers we face, but because engagement can more durably lift suspicion and fear. America will remain the anchor of strong alliances in every corner of the globe. And we will renew those institutions that extend our capacity to manage crisis abroad, for no one has a greater stake in a peaceful world than its most powerful nation. We will support democracy from Asia to Africa, from the Americas to the Middle East, because our interests and our conscience compel us to act on behalf of those who long for freedom. And we must be a source of hope to the poor, the sick, the marginalized, the victims of prejudice –- not out of mere charity, but because peace in our time requires the constant advance of those principles that our common creed describes: tolerance and opportunity, human dignity and justice.

And at some point, I know that one of my daughters will ask, perhaps my youngest, will ask, "Daddy, why is this monument here? What did this man do?" How might I answer them? Unlike the others commemorated in this place, Dr. Martin Luther King Jr. was not a president of the United States — at no time in his life did he hold public office. He was not a hero of foreign wars. He never had much money, and while he lived he was reviled at least as much as he was celebrated. By his own accounts, he was a man frequently racked with doubt, a man not without flaws, a man who, like Moses before him, more than once questioned why he had been chosen for so arduous a task — the task of leading a people to freedom, the task of healing the festering wounds of a nation's original sin. And yet lead a nation he did. Through words he gave voice to the voiceless. Through deeds he gave courage to the faint of heart. By dint of vision, and determination, and most of all faith in the redeeming power of love, he endured the humiliation of arrest, the loneliness of a prison cell, the constant threats to his life, until he finally inspired a nation to transform itself, and begin to live up to the meaning of its creed. Like Moses before him, he would never live to see the Promised Land. But from the mountain top, he pointed the way for us — a land no longer torn asunder with racial hatred and ethnic strife, a land that measured itself by how it treats the least of these, a land in which strength is defined not simply by the capacity to wage war but by the determination to forge peace — a land in which all of God's children might come together in a spirit of brotherhood. We have not yet arrived at this longed for place. For all the progress we have made, there are times when the land of our dreams recedes from us — when we are lost, wandering spirits, content with our suspicions and our angers, our long-held grudges and petty disputes, our frantic diversions and tribal allegiances. And yet, by erecting this monument, we are reminded that this different, better place beckons us, and that we will find it not across distant hills or within some hidden valley, but rather we will find it somewhere in our hearts.