The Colliers' novel explores the tension between ideological beliefs and personal relationships. In "My Brother Sam Is Dead," the Meeker family faces a difficult choice between their political beliefs and family loyalty, leading to potential tragedy both privately and publicly. The book presents the Revolutionary War as a civil conflict that divides families and communities. The authors illustrate how war unleashes forces that cause unpredictable outcomes, affecting both those who die in battle and those whose lives are disrupted by the turmoil.

Sam Meeker, a sixteen-year-old Yale student, believes in the righteousness of the rebel cause and, like many of his peers, wishes to join the militia. However, he falls short of his noble ideals, displaying laziness and a penchant for drinking and swearing, which, according to his brother, tarnishes the family's honor. Their father, Life Meeker, owns a tavern and general store. A veteran of the French and Indian War, he is proud but does not desire to rebel against England. Like Sam, he is argumentative and stubborn but deeply loves both his family and his country. Fourteen-year-old Tim Meeker looks up to both his brother and father. As the story’s narrator, Tim allows readers to witness his journey from innocence to a more mature understanding of reality. Caught between his affection for Sam and his loyalty to Life, Tim hesitates to take sides. His focus on his family's everyday needs, even during wartime, makes him a relatable character. Over time, Tim matures, realizing that his youth does not make him lesser than his older brother. He takes on family responsibilities, unlike Sam, who leaves to pursue his own glory.

Tim's mother, Susannah Meeker, is a proud British subject who strives to maintain family harmony. Strong and compassionate while her husband is alive, she supports his views. However, after his death, she becomes disillusioned with the war, especially when she learns that Sam plans to re-enlist instead of returning home to assist the family. Tom Warrups, a Native American who is poorly treated, lives in fear of white society but is willing to take risks for his friend Sam. Sam's girlfriend, Betsy Read, the daughter of the affluent Colonel Read, has only a vague understanding of war but supports Sam's beliefs, aiding him in stealing his father's gun and running away. Although Betsy's character is somewhat stereotypical compared to others, she eventually realizes that Sam loves war more than he loves her or his family.