One of the main themes is often slavery and the moral wrongs associated with it. Stowe was very much against slavery, and this is evident in her works. Her stories might also touch on themes of family, as she shows how families are affected by the institution of slavery.
Well, in her short stories, Harriet Beecher Stowe often delved into the theme of social justice. Slavery was a huge social injustice of her time, and she used her stories to expose it. Additionally, the idea of human dignity is a theme. She wanted to show that all humans, regardless of race, have dignity and should be treated as such. Her stories were a way to make people think about these important concepts.