why did jem cry after he heard the jury's verdict?

This was the end of innocence for Jem. He has witnessed bigotry, ignorance and hate first hand. Despite overwhelming evidence that Tom Robinson was a falsely accused man the white jury found him guilty of the rape of Mayella Ewell. Despite his father's heroic efforts to appeal to the jury's sense of humanity, they still condemned Tom Robinson. This made Jem cry.