Angela and her family have arrived in New York City from their village in Italy to find themselves settled in a small tenement apartment on the Lower East Side. When her father is no longer able to work, Angela must leave school and work in a shirtwaist factory. Against the backdrop of the birth of the labor union movement in the early 1900s, Angela plays a part in the drama and turmoil that erupt as the workers begin to strike, protesting the terrible conditions in the sweatshops. And she records the horrors of the Triangle Factory fire and the triumphs and sorrows of the labor movement.