Final answer:
Dill cries in 'To Kill a Mockingbird' after being deeply affected by the racial injustice observed during Tom Robinson's trial, which represents a loss of innocence.
Step-by-step explanation:
In Harper Lee's novel To Kill a Mockingbird, Dill is crying after witnessing the injustice that prevails in the courtroom during Tom Robinson's trial. The trial reveals the racial prejudices and inequalities of the justice system in the deep South, which deeply affects Dill who is sensitive to the wrongful treatment of others. Dill's tears symbolize the loss of innocence as he confronts the harsh realities of the world around him.