Cambridge Street picks up the Tomaso saga on a sweet-smelling farm in Sicily. Tomas and Katerina have three boys: Paolo, Renzo, and Leonardo. On the verge of poverty and after getting caught up in a Mafia web of violence, the family decides to send their sons to America. It is a heart-breaking separation: each must say good bye to the people they love knowing they will likely never see them again. In America, at the dawning of the Roaring Twenties, the arrivals must adjust to life as unskilled laborers in the squalid city of Chicago, living in the tenements on Cambridge Street. They want to grow their families in peace but soon they are confronted by the same murder, terror, violence, and organized crime they tried to flee. Men from the Old Country with names like Malo Tancredi, Gazzo and Lupo run the people and businesses here like they did back home. The obstacles to a peaceful life seem insurmountable and inevitable. When an act of stunning and horrible violence is committed against them by their own countrymen, the Tomasos must decide on a course of action that will define them as people and determine the futures of their children.