A small object from the past can stir up so many thoughts. When I hold the shards of stained glass from the 16th Street Baptist Church, I see people gathering for worship and children bent over their Sunday school books. I hear a choir practicing and, out of nowhere, I hear a fierce sound of death and damage delivered by hate.

Soon, we hope visitors to the National Museum of African American History and Culture will see the shards, given to us by white activists from the 1960s civil rights movement, and be stopped, and renewed, by their symbolism.

We still hear the explosion in our hearts, in the images of the young girls who are frozen in their innocence, in the seemingly never-ending stories of violence in every corner of our country. It took a blast at 10:22 in the morning to create a day that remains one of the most tragic in American history 50 years later.

We will never forget; no one should. But we need to remember just how horrible that year of violence had been in Birmingham. It finally alarmed people outside the South to the city’s hatred and cruelty when dogs and water hoses were used on children marching for justice. We need to remember the resilience of those children who kept marching and the vision of the Rev. Martin L. King Jr. as he wrote “Letter From Birmingham Jail.”

Yet the war on the people of Birmingham was far from over. An explosion shattered the peace of a Sunday morning, robbing girls of their adulthood and snatching lives of promise from their families. In the aftermath, just days after the euphoria of the March on Washington, King delivered a rebuke that crackled with outrage and pointed fingers at those who had been complacent up to that point. He blamed “every Negro who refuses to go down and register to vote.”

Looking back at this long road we call history, we have always sacrificed, giving up severe losses to make gains. The men storming the beaches of Normandy. Our first responders in bombings, fires and accidents. And Addie Mae Collins, Cynthia Wesley, Carole Robertson and Denise McNair.

Fortunately we have witnesses to the Sept. 15, 1963, tragedy who understood the meaning of that loss. Joan Mulholland, a Freedom Rider, gave us the first shards. Just this week, the children of the Rev. Norman C. “Jim” Jimerson, a civil rights worker in Birmingham, gave us an additional shard. He picked up an 8-inch piece with a large rosette and leading from the rubble that afternoon.

In their generous donations, they have vowed never to forget. And always to honor the memory of the girls, projecting lessons for our own children, and those who will follow. Ann Jimerson, who said the shard had always been a reminder to her family to fight for social justice, explained the gift was inspired in part by the aspirations President Obama outlined at the groundbreaking of our museum last year. He spoke of his daughters. “I want my daughters to see the shackles that bound slaves on their voyage across the ocean and the shards of glass that flew from the 16th Street Baptist Church, and understand that injustice and evil exist in the world. But I also want them to hear Louis Armstrong’s horn and learn about the Negro League and read the poems of Phyllis Wheatley. And I want them to appreciate this museum not just as a record of tragedy, but as a celebration of life.”

Over the years, this charge has been taken up by artists. Spike Lee, the filmmaker, produced an Oscar-nominated documentary about the loss. Showing at the Kennedy Center on this week’s anniversary is a play on the day written by playwright Christina Ham and directed by actress Phylicia Rashad. Many books, poems and music have immortalized the horror. Randall C. Jimerson has a forthcoming family memoir, “Shattered Glass in Birmingham: One Family’s Fight for Civil Rights, 1961-1964.”

The shards are the proof of an erasable act. The shock at the bombings led to the Civil Rights Act of 1964 and the Voting Rights Act of 1965. Violence is a travesty, even as we remember our country’s beginnings, battles of ragtag soldiers, the murder of a president, prophets and men just walking. Yet we need to vow once again on Sept. 15 to erase that destructive element from America’s image.

Bunch is founding director of the Smithsonian’s National Museum of African American History and Culture.