My Brother Sam is Dead begins in 1775, when the New England colonies were just beginning to join forces in rebellion against their ruler, the mighty British government. Since their founding, the colonies had paid taxes to the king of England, retained many British customs, and often followed the Anglican religion. By the time when this story takes place, the movement for independence had begun to spread through the land, gaining great following at the universities, including Yale, where the fictional character Sam Meeker is a student. The Boston Tea Party had happened, exciting the rebel Patriots and offending the Tories, New England men who remained loyal to England. The colonies were beginning to divide in their loyalty. The makeshift rebel militia, the Minutemen, rose under the leadership of George Washington and defeated the British forces in the battle of Lexington and Concord, an event Sam notes in chapter one. Even with so much pro-Patriot sentiment, Redding, Connecticut, where the Meekers live, was a Tory town. It is a historical fact that Redding inhabitants endured aggression and the stealing of their guns and cattle, partly out of wartime desperation for goods, and partly out of animosity toward the Loyalists.

This novel was written to recreate a particular moment in the Civil War from the viewpoint of a child. The novel is sometimes offensive; when Tim Meeker describes the seating in the church, he notes without judgment that the balcony is where those deemed lesser humans sit— children, black people, and Indians. Women defer to the judgment of their husbands, and therefore when Tim returns to help his mother run the tavern, he acts as the master of the property.

This novel questions the usefulness of war as an answer to social problems. At the end of the novel, Tim asks us whether such a nation could be created from an end other than war. My Brother Sam is Dead demonstrates the repercussions of war on a single involved family, and through this suggests the possible effects on each other group of individuals. But overall, this novel does not carry an antiwar message so much as it details the maturation of a boy who adores and idolizes his older brother, and how the wartime situation brought out the younger brother's abilities and principles in contrast to those of the older.

The authors of this novel take many of their characters from history. A Meeker Tavern did exist in Redding, and many of the city inhabitants lived and died in the same manner that they do in the novel. In an epilogue, the brothers Christopher Collier and James Lincoln Collier explain their endeavor to recreate the effects of war on this Tory family. James Collier writes many children's books and magazine articles, and Christopher is a professor specializing in the history of the American Revolution.