To celebrate the 50th anniversary of Martin Luther King Jr.'s historic "I Have a Dream" speech at the 1963 March on Washington, TIME Magazine asked several important people what the speech means to them. Here are some of their responses.

In many ways, the March on Washington was a culmination of actions from Dec. 1, 1955, to Aug. 28, 1963. We were on the dawn of a new day, and it had taken daylight a long time to come. The essence of Dr. King's speech was not the dream; it was the broken promise.

We had been promised the accommodations of full citizenship, the right to vote. We had been promised equal protection under the law and equal opportunity. Yet in our quest for citizenship, the promise was broken.

The spirit at the march was that we were winning, and we were doing it together. Blacks, whites--we were a multiracial social-justice coalition. That was before we had the public accommodation and before we had the right to vote. But those victories were in sight.

We had this sense that we were winning; we were rising up. We had overcome fear. That speech was an early indication that if we keep marching, if we keep pushing, we're going to win this battle. It was a dawn-to-daylight speech, and we won.

Now we have the sense that we're at dusk, moving toward midnight. One thing we can learn from Dr. King is that the forces of equal protection should neither sleep nor slumber. We got the right to vote in 1870 after 200 years of slavery. In 1965 we got the Voting Rights Act, but in 2013 the Supreme Court eviscerated it. The struggle for democracy and equal protection will never be a past-tense discussion.

We've got to keep marching.

–By Jesse Jackson

I was in Vietnam in August 1963. I was not able to see or hear Dr. King's speech, and in those days the news to Vietnam traveled slowly. My wife Alma was in Birmingham with our infant son. During that ugly summer, my father-in-law stood guard to protect my family while I was fighting for our country 8,000 miles away.

I returned home to find America embroiled in a second Civil War, one led by Dr. King. It was a war of morals, righteousness and the aspirations of our Founding Fathers. The "I Have a Dream" speech held up a mirror for all Americans to look deeply into the spirit and soul of our country.

The "Dream" speech, along with the Civil Rights Act and Voting Rights Act that followed, finally broke the bonds of segregation and Jim Crow that had imprisoned our finest dreams. Not only were African Americans given a berth of freedom, but white America had a horrible burden removed from its back. Fifty years later, we have seen great progress. But we are not yet where we need to be. Education, jobs, health care and good housing for all Americans must remain our goal. We all must work together if Dr. King's dream is to be fully realized.

—By Colin Powell

It was 50 years ago when the Rev. King had that dream and dared to say so, that little black children in Florida and in Mississippi and in Georgia and in South Carolina would stand with little white children and hold hands, that they themselves would dream the dream. What a dream. Can you imagine if we did not have this undergirded hate and racism, prejudices and sexism and ageism? If we were not crippled by these idiocies, can you imagine what our country would be like?

This is not to say we have not had progress--in fact, tremendous progress. After the lives and deaths of Martin Luther King Jr. and Malcolm X and the Kennedys and Fannie Lou Hamer--young people may say, You mean it is no better? But it is better.

There is still hope. If there were not, there would be no reason to get up in the morning. There is hope. Sometimes you need to be jarred into finding it, jarred into sharing it. I remember a statement of the Rev. King's that you ought to believe something in life, believe in something so fervently that you will stand up with it until the end of your days. I think we all have to believe that the day will come that we do not have to be saddled; we will not be crippled with all this idiocy. I hope for that. I am still working for it. I am still writing for that. I speak of that. I sing about that. I pray about that.

—By Maya Angelou

Martin Luther King Jr. inspired millions of people, including me, to dream. His words—still so powerful after half a century—empower us to continue the journey to our destination of peace and equality. He was, of course, a great human-rights activist and leader. He stood up against segregation and inspired America to be a country for people of all colors and creeds. He raised his voice for freedom with honesty. He dreamed and changed the world with a few unforgettable, powerful words.

His legacy is that those words reached far beyond America's shores and far beyond the generation to whom he spoke. They are relevant today. They are relevant to me, a girl born almost 30 years after he died, from a country more than 7,000 miles away.

My dream is to see every child with a book and pen. I dream that every woman in the world will be treated with dignity and equality. Fifty years on from his famous oration in Washington, D.C., I have a dream too.

—By Malala Yousafzai

Martin Luther King's "I Have a Dream" speech should be required reading for every American. Like the Declaration of Independence and the Gettysburg Address, it is an elegant, passionate and unforgettable distillation of the aspiration and inspiration of America. In just a few paragraphs, King expressed his anguish at unfulfilled promises, the urgency facing America to live up to its ideals and his abiding faith that it could and would do so.

King pronounced the time for patience to have expired and shared his deeply rooted conviction that his dream would, at long last, coalesce. He made clear that the need for action was immediate and compelling, while exhorting blacks to renew their faith in America. There has been no greater reminder of what this nation held itself out to be and no greater plea for us to attain those ideals. No greater invocation of the spirit of Jefferson and Lincoln. No greater manifesto for America.

—By Theadore B. Olsen

I've known large parts of this speech by heart since before I could read. My father likes to quote the words of great men at the dinner table. King's definitely qualified.

To me, a child born in the '70s, the words of his speech seemed vaguely confusing. What was the fuss? King had a dream, and it came true: I held hands with the little white girl next door almost every day when I went out to play. As I got older, I came to realize that while King's dream had become something of a reality in small pockets of America, in the larger world it was more ethereal.

We are living in a strange time in terms of race in this country. We're teetering on a tightrope between greatness and madness. A man of color can be President of the United States. A man of color can be shot for wearing a hoodie. We haven't gotten to King's promised land. There's still work to be done.

—By Shonda Rhimes

A half-century has passed since Dr. Martin Luther King Jr. stood on the steps of the Lincoln Memorial to awaken our nation's conscience. His vision was simple yet profound: that America must fulfill the promise made in her founding documents by allowing every citizen to access their God-given rights.

Dr. King helped bring hope to men and women of all backgrounds who wished to contribute to American exceptionalism. That included immigrants like my parents, who made a new life here after coming from Cuba. They immigrated in 1956--the year Dr. King led the Montgomery bus boycott--and raised my siblings and me in the wake of his legacy, telling us our dreams were possible regardless of the circumstances of our births.

I have taken my own children to the Lincoln Memorial and shown them where Dr. King spoke to the unfulfilled promise of our nation. Standing in that place, I was filled with pride to know my children live in a nation where the cultural landscape is dramatically different from the one that Dr. King saw just 50 years before.

Dr. King reminded us that opportunity and freedom are American ideals, belonging to no singular demographic. His message and legacy must live all around us and his dream must continue to lead us as we move toward America's brightest days.

—By Marco Rubio

I am proud to say that I owe my political career to the inspiration that came from Dr. Martin Luther King Jr.

I first met Dr. King and his wife Coretta in the early 1960s. After the Supreme Court upheld the principle of "one person, one vote," Michigan was required to create a new congressional seat in Detroit, which I ran for in 1964. Thanks to the recommendation of my good friend Rosa Parks, I became the only congressional candidate ever endorsed by Dr. King.

I was proud to cast one of my very first votes in Congress for the Voting Rights Act of 1965. That document, along with the 1964 Civil Rights Act and the 1968 Fair Housing Act, is a crown jewel of our civil rights laws. They represent the very spirit of King's "I Have a Dream" speech (a phrase he first used in the Freedom March in Detroit, two months earlier).

Despite the historic election of our first African-American President, the challenges remain daunting. In June the Supreme Court weakened the Voting Rights Act at a time when many states are adding onerous new voter-ID requirements. Affirmative action is under assault in the courts. Our schools are becoming resegregated. But these challenges are not insurmountable. Through a renewed commitment to the teachings of Dr. King, we must keep the struggle alive.

—By John Conyers

Fifty years ago, the No. 1 issue for African Americans was blatant discrimination. Due in part to Dr. King's powerful words, the country passed legislation that led us away from Jim Crow and moved us toward embracing our differences and seeing them as a source of strength.

Today, though, we still have a black-white achievement gap in education and deeply troubling statistics about incarceration, substance abuse and unemployment. They tell us Dr. King's dream has not been fully realized. Our country has come a long way in terms of civil rights, but we still have a long way to go.

Education is the key to achieving the dream. Our public-education system, the step up for so many Americans, is failing to prepare huge numbers of our children for the future. That threatens the dream for all of us.

—By Geoffrey Canada