It is early twentieth century in New York. In New Rochelle live the members of an upper-class white family: Little Boy, Father, Mother, her Younger Brother, and Grandfather. In Harlem, Sarah, a black woman, falls for the popular ragtime pianist Coalhouse Walker Jr. And in the Lower East Side living in utter poverty are Jewish immigrant Tateh and his daughter. All hope to be part of the American Dream.
Father, who owns a fireworks factory, prepares to travel on a year-long expedition to the North Pole and leaves everything in the capable hands of his wife, who somehow knows that the world will change while he is gone.
Not long after, Mother is surprised to discover a black newborn baby in her garden. The baby is still alive, and the police find Sarah, the mother, nearby. Mother has pity on them both, takes responsibility for them, and welcomes them into her home.
Tateh is full of hope as he sets up his artist stand on the street to earn money for him and his daughter. His dreams slowly turn to dust as they barely survive in the terrible immigrant tenements in which they are forced to live. Meanwhile Coalhouse Walker is heartbroken in Harlem because Sarah has left him. He hears where she might have gone, and he proudly purchases a new Model T to find and impress her.
Coalhouse arrives at Mother’s house, where he first learns of the existence of his baby boy. Sarah refuses to see Coalhouse, so he resorts to returning weekly until Mother invites him inside. He introduces the family to ragtime music just as Father returns, stunned by the changes in his family’s life and not understanding the social and racial tensions that are simmering under the surface. But Mother and Younger Brother are proud of their choices. Sarah also enters and reconciles with Coalhouse.
Tateh has now left the city and works in a textile factory in Massachusetts where the activist Emma Goldman is fighting to improve the horrible working and living conditions for immigrants. Younger Brother attends her rally and decides to join the cause. The textile factory workers go out on strike, which turns into a riot, and Tateh takes his daughter and flees on a train to Philadelphia. While they travel, Tateh creates a flipbook to calm his daughter, and the train conductor sees it. Intrigued, he wants to buy the book, and Tateh, hurriedly dubbing it a “movie-book,” sells it for a dollar. He quickly realizes this may be his route out of poverty.
Back in New York, after an evening out, Coalhouse and Sarah are accosted by the bigoted Willie Conklin and the fire squad. Because of their prejudice towards black people, they viciously destroy his Model T car. Coalhouse demands restitution but is rebuffed at every turn, eventually vowing the he will get justice on his own terms. Younger Brother joins with Coalhouse, Emma Goldman, and other Coalhouse supporters in their fight for justice and equality for all oppressed people. Unsuccessful, they vow to “go out and tell our story.” Ultimately, the age of ragtime ends, and the characters each do tell their stories, leading to a tragic, hopeful, and dream-laden denouement.
