Less than three weeks after the peaceful, triumphant March on Washington, four Ku Klux Klan members planted a box of dynamite under the steps of the 16th Street Baptist Church in Birmingham, Ala.
The explosion that ripped through the building on Sept. 15, 1963, killed four young black girls—Carole Robertson, Cynthia Wesley, Addie Mae Collins (all 14 years old) and Denise McNair (11)—and injured 22 others, including Addie's younger sister Sarah. Frank Dandridge's photo of 12-year-old Sarah, with bandages covering her eyes, was a grim reminder that murderous opposition to the civil rights struggle remained.
Sarah Collins Rudolph, who never regained sight in her left eye and lives with her husband George not far from Birmingham, is still fighting for restitution for medical expenses and suffering at the hands of the Klan.
"It's just such an awful, awful shame," she says, "that it took that much violence for some people to finally wake up to what was happening in their own country."
A year after the March on Washington, Martin Luther King Jr. was awarded the Nobel Peace Prize and celebrated the passage of the Civil Rights Act. The Voting Rights Act passed in 1965, and in 1967, King publicly declared his opposition to the war in Vietnam. His antiwar stance alienated King from other leaders in the civil rights movement and fractured his relationship with the Johnson Administration. By 1968, the year he was assassinated, King had ceded some of the civil rights movement’s limelight to other figures, while melding his demand for social justice, his support for the poor and his opposition to the war into a unified theory of nonviolent revolution.
When civil rights activists announced a voting-rights march from Selma, Ala., to the capital, Montgomery, in 1965, few expected the protest to go unchallenged. But even the most pessimistic observers were shocked by the ferocity of the attacks on protesters by Alabama state troopers on March 7, 1965, a day that became known as Bloody Sunday.
It would take two more attempts—the second was also turned back by force—before marchers finally made it onto the steps of the state capitol on March 25. Months later, Congress passed the Voting Rights Act of 1965. On the eve of the third, successful march, LIFE published a cover story highlighting the brutality of the first two marches.
On April 4, 1968, LIFE photographer Henry Groskinsky and writer Mike Silva, on assignment in Alabama, learned that Martin Luther King Jr. had been shot at the Lorraine Motel in Memphis. The two men jumped into their car and raced 200 miles to the scene of the assassination. Once there, they were astonished to discover that they had unfettered access to the motel's grounds, to nearby abandoned buildings from which the fatal rifle shot likely came, to King's motel room and to the bleak, blood-stained balcony where the civil rights leader had fallen, mortally wounded, hours earlier.
Groskinsky's photographs from an unsettlingly quiet Memphis were never published in LIFE. Forty-five years later, they remain among the most chilling pictures from a tumultuous, harrowing era.
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.
Dr. King said, Here we are a hundred years after 1863, and in Lincoln’s majestic shadows we stand. You promised, Congress, with the 13th and 14th Amendments, you promised. Yet here we stand today, with a broken promise, a “bounced check, marked insufficient funds.” 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 1865 after 200 years of slavery. By 1965 we got the Voting Rights Act, but in 2013 they eviscerated it. The struggle for democracy and equal protection will never be a past-tense discussion. There’s always a need for equal protection.
We’ve got to keep marching.
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.
To mark the 50th anniversary of the March on Washington and Martin Luther King Jr.'s "I Have a Dream" speech, TIME presents a special commemorative issue—featuring Jon Meacham on King as a Founding Father of the 21st century; Richard Norton Smith on how King's words changed the nature of presidential persuasion; Michele Norris on the state of the dream today; plus Maya Angelou, Malala Yousafzai, Jesse Jackson, Colin Powell, Shonda Rhimes, Marco Rubio, Charlayne Hunter-Gault and more on what "I have a dream" means to them. Join TIME.com to read the full issue
If you asked back then [if] Barack Obama
would be in the White House today,
we would say no way.
We didn’t even dream
of anything like that.
This portrait of President Obama, taken by White House photographer Pete Souza during a September 2012 meeting in the Oval Office, puts the first African-American President in striking context: he shares the room with George Washington, Abraham Lincoln and Martin Luther King Jr. The bust of King was created by celebrated African-American sculptor Charles Alston in 1970.
At the 2011 dedication of the Martin Luther King Jr. Memorial on the National Mall, President Obama praised King for his speech at the March on Washington but cautioned that more work remains. Said Obama: "It is right for us to celebrate Dr. King’s marvelous oratory, but it is worth remembering that progress did not come from words alone. Progress was hard. Progress was purchased through enduring the smack of billy clubs and the blast of fire hoses. It was bought with days in jail cells and nights of bomb threats … Let us remember that change has never been quick. Change has never been simple, or without controversy. Change depends on persistence. Change requires determination."
“We as political players and leaders, we cannot just be concerned about the next election. We’ve got to be concerned about what has happened to our people and all the citizens. Courage is what is needed. The people who participated in the March on Washington or the march from Selma to Montgomery, black and white, they displayed raw courage. People who spoke up for civil rights and people who are speaking up today for immigration reform, for gay rights, for control of the proliferation of guns, they are showing some courage. But too many people are prepared to run and hide.
We need people to lead, to get out front on some of the big issues and not be afraid to be bold, to be courageous and to be a headlight and not a taillight. That’s what is needed.”
Photographer Camilo José Vergara has spent his career photographing some of the poorest and most segregated communities in the U.S. Over the past three decades, he has documented murals and signs, many featuring Martin Luther King Jr., in cities across the country. In these hand-painted tributes, King appears in a variety of guises: as the everyman, the martyr, the mythic hero, alongside African-American and Latino heroes and, in recent years, in company with President Barack Obama.
We are now celebrating the “I Have a Dream” speech at the same time that there are people in the street again, all over the country, protesting the Zimmerman trial. Here we are—it was exactly 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 hope, there would be no reason to get up in the morning. There would be no reason to shower and brush one’s teeth, to try to put on coordinating colors. 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.