The theme of a story is what the author is trying to convey — in other words, the central idea of the story. ... The plot is simply what happens in the story and the order of the story's events, and the moral is the lesson that the writer wants the main character (and by extension, you) to learn from the story.
The answer above is completely incorrect. The actual answer is going to be the second option: They shared the belief that rights granted by the US Constitution should apply to all Americans. Hope it helps.