At 10:22 AM on Sun., Sep. 15, 1963, a bomb went off at the Sixteenth Street Baptist Church in Birmingham, Alabama. Though the previous spring the church had been used as a staging ground for Martin Luther King Jr.'s Birmingham Campaign -- a non-violent protest against racial segregation -- on that day it was merely a meeting place for Sunday school attendees. Four girls were killed in the blast, three of them 14 years old; the other 11.

Three days later, Dr. King performed the eulogy to a crowd of 8,000 mourners. While King bemoaned the loss of "these children -- unoffending, innocent, and beautiful," he also used the tragedy as a call to action: "God still has a way of wringing good out of evil," he said. "The innocent blood of these little girls may well serve as a redemptive force that will bring new light to this dark city."

The so-called "Bombingham" terrorist act proved one of the darkest hours of the Civil Rights movement, and King's eulogy one of the most galvanizing. Outraged citizens -- both white and black -- joined the cause of desegregation. Artists like Nina Simone and Joan Baez sang about the bombing, while jazz saxophonist John Coltrane composed his infamous "Alabama" based on the cadences of King's speech.

It wouldn't be until the following year that President Johnson would sign the Civil Rights Act into law. But without the tragedy in Birmingham, it might very well have been much longer. "You gave to this world wonderful children," King said to the parents of the slain girls. "They didn't live long lives, but they lived meaningful lives."