It is 1846 when twelve-year-old street urchin Ian Walsh and his eleven-year-old drummer friend Danny Higgins decide to abandon their hardships and travel from Ireland to America. With hopes of landing jobs building a railroad in California and finding the lost cities of gold, Ian and Danny board a cargo ship bound for New York.
As the ship sets sail on the sea, Danny—affectionately nicknamed “Smiles” by the crew—is happier than he has ever been. Once Ian finds his sea legs, he contentedly spends his days perched at the bow of the ship writing in his diary. After a twenty-three-day journey across the Atlantic, the ship docks in the port of New York. The two boys soon learn that the United States is at war with Mexico and that the President is calling for volunteers to meet the Mexican threat. There is no question—Ian and Danny feel compelled to help and sign up as drummer boys in the First New York.
As the two boys begin a new life in a country in the midst of great change, they learn to rely on their instinct, scrappiness, and most of all, courage.