Dawn's Early Light tells the story of Julian Day, a young British man newly arrived in Williamsburg, Virginia, who soon meets John Sprague. With the colonies in a rebellious mood, Day, who had not given the matter much thought, finds he must soon choose loyalties; does he belong here, in Virginia with the Spragues, or back in his old country?
Colonial Williamsburg also hosts the lower class, the down-trodden of society, including young Tibby Mawes and her twin brother Kip, who Julian first meets when they are about nine years old--in the company of an abusive, alcoholic father. The father is soon removed from the picture, and Kip becomes one of Julian Day's students. Tibby eagerly desires schooling too, but since that is not allowed for girls, Julian arranges for her proper education as a young lady of the higher social class.
Over the years, Tibby and Julian become closer, though Julian, twelve years older than Tibby, has his eyes set on other women. Set during the American Revolution, Dawn's Early Light also includes interaction with real historical figures such as the French General Lafayette, and historical events including the British invasion of Williamsburg.