It was her first civil rights demonstration. Shirley Green-Reese was 13 when she challenged segregation outside the Martin Theater in Americus, Ga., in July 1963.

She tried to buy tickets at the front of the theater instead of entering from the back alley. That’s when the police arrived.

“We were just children. We didn’t think nothing could happen to us,” said Green-Reese, now 72, of the moments before she was arrested. “We just didn’t know the danger of it.”

She had gone to the protest without her parents’ knowledge and figured she could make it back home before they did. She wouldn’t.

Instead she was transported from cell to cell in rural southwest Georgia before finally ending up in a stockade in Leesburg, where she was among 15 girls imprisoned for at least 45 days without ever being charged with a crime. The children, who ranged in age from 12 to 15, eventually became known as the Leesburg Stockade Girls.

But for a long time, their parents had no idea where they were. They were still locked up during the March on Washington on Aug. 28, 1963, when the Rev. Martin Luther King Jr. delivered his “I Have a Dream” speech in front of the Lincoln Memorial.

Green-Reese had never slept away from home without her parents. She was terrified.

And the conditions inside the Civil War-era structure in the backwoods of Lee County were appalling. The toilet was rusted out and didn’t work. There were no beds. Shattered glass littered the concrete slab floor. The only running water dripped from a leaky shower head.

“It smelled like feces had been there for years,” Green-Reese said. “We didn’t know if we were gonna live or die.”

In the middle of a Georgia summer, the concrete stockade was sweltering. Eventually, Green-Reese used a piece of her clothing like a rag to wipe down a spot on the filthy cement to sit. It became her makeshift bed, though she and the others could barely sleep.

To drink water and try to wash themselves and their clothes, the girls would cup their hands underneath the shower head, a painstaking process. The water was always hot, but that was all they had.