Why did mother and father argue about Sam's letters in my brother Sam is dead?

In "My Brother Sam Is Dead," Mother and Father argue about Sam's letters because they represent conflicting views on the Revolutionary War. Father, who is loyal to the British, is deeply concerned about Sam's involvement in the rebellion and feels that his letters reflect a dangerous and rebellious spirit. Mother, on the other hand, is torn between her love for her son and the fear for his safety, leading to tension as they struggle to understand each other's perspectives on loyalty and family. This conflict highlights the broader themes of division and the personal impact of war.