The story runs in the 1910's New York. Coalhouse Walker Jr. is a black piano player. He has won fame and fortune playing with a jazz band. Some white men do not like this situation, and one day they assault him and spoil his brand new car. Walker tries by all means to get justice, without an answer...
A young black pianist becomes embroiled in the lives of an upper-class white family set among the racial tensions, infidelity, violence, and other nostalgic events in early 1900s New York City.
- The film begins with a newsreel montage, depicting celebrities of the turn of the 20th century such as Harry Houdini, Theodore Roosevelt and the architect Stanford White (Norman Mailer), as well as life in New York City. The newsreel is accompanied by ragtime pianist Coalhouse Walker, Jr. (Howard E. Rollins, Jr.).
The millionaire industrialist Harry Kendall Thaw (Robert Joy) makes a scene when White's latest creation, a nude statue on the roof of Madison Square Garden, is unveiled. The model for the statue is Evelyn Nesbit (Elizabeth McGovern), a former chorus girl who is now Thaw's wife. Thaw becomes convinced White has corrupted Evelyn and humiliated him. On the evening of June 25, 1906, Thaw confronts and publicly shoots White during a show at Madison Square Garden, killing him in cold blood before several witnesses. Thaw surrenders to the police without attempting to run.
Meanwhile, an unnamed upper class family resides in a comfortable suburban home in New Rochelle. The family's Father (James Olson) owns a factory, where his wife's Younger Brother (Brad Dourif) is employed as a fireworks maker. Their passive, sheltered existence is disturbed when an abandoned African American baby is found in their garden. The child's mother, an unmarried washerwoman named Sarah (Debbie Allen), is discovered, and brought to their home. When she learns that the police intend to charge Sarah with child abandonment and attempted murder, Mother (Mary Steenburgen) intervenes and takes both Sarah and her child into the home, despite Father's objections. Some time later, Coalhouse Walker arrives at the house in search of Sarah, driving a new model T-Ford automobile and acting in a brash manner unlike the subservient attitude expected of the African American community at the time. Realizing that he is the baby's father, he announces to a skeptical Father that he intends to marry Sarah.
Younger Brother witnesses White's murder and becomes obsessed with Evelyn, leaving home for long periods of time to follow her throughout the city. Thaw's lawyer, Delphin (Pat O'Brien), bribes Evelyn with a million-dollar divorce settlement (which she accepts) to keep silent about Thaw's mental instability at his trial and to testify that White had abused her when she was a teenager to model in the nude for him.
Passing through the tenements of the Lower East Side, Evelyn encounters a Jewish street artist known as Tateh (Mandy Patinkin) and witnesses him throw his wife (Fran Drescher) out of their home after learning of her infidelity. Tateh takes their daughter and leaves New York, taking with him the flip book he has invented, which he begins to sell successfully. Evelyn, who has become fond of the little girl, is troubled by their disappearance, but distracted when Younger Brother declares his love to her. She begins an affair with him as she begins to plan her return to the stage. He assumes that they will eventually marry and plans to introduce her to his family.
A year-and-a-half later (in early 1908), Thaw is tried and found not guilty by reason of temporary insanity for White's murder. That evening, Delphin and his assistant counsel (Richard Griffiths) interrupt one of Evelyn's sexual trysts with Younger Brother and inform her that Thaw will be suing her for divorce on the grounds of infidelity, offering her a much smaller divorce settlement, which she takes. The affair ends shortly thereafter, leaving Younger Brother alone and adrift.
A little later, trouble rears its head in New Rochelle when Coalhouse Walker is targeted by a crew of bigoted volunteer firemen, led by fire chief Willie Conklin (Kenneth McMillan), who refuse to allow his automobile to pass by their firehouse. After he leaves to find a policeman (Jeff Daniels), Walker returns to find his car's seat soiled with horse excrement. His protests end with the racist policeman placing him under arrest for parking his car illegally. Conklin is not arrested.
After Father arranges for Walker's release on bail, they discover his car has been vandalized further. He pursues legal action against the fire company, but can find no lawyer willing to represent him. Father, who believes Walker has no legal recourse open to him due to his race, and Younger Brother, who supports Walker, have a confrontation in front of Sarah, who is informed by an infuriated Father that it is up to her to get Walker to see sense. She sneaks out of the house to attend a presidential rally, where she attempts to tell President Teddy Roosevelt about Coalhouse Walker's case but is pushed back and beaten by the racist guards. She is severely injured, and soon after dies from her wounds.
After Sarah's funeral, a furious Coalhouse Walker assembles a group of African-American supporters where they ambush the volunteer firemen, killing several of them. He sends a letter to the police and newspapers threatening to attack other firehouses, demanding that his car be restored and that Conklin be turned over to him for justice. Father is disgusted at Walker's violence, but Younger Brother tracks him down and joins his gang, bringing with him his knowledge of explosives.
Ostracized by their community and hounded by reporters over their involvement in a black man's issues, Father and Mother leave New Rochelle for Atlantic City, where they encounter Tateh, who is now a film director working on a photoplay with Evelyn Nesbitt. Mother is attracted to him, and she and Father quarrel.
Meanwhile, Coalhouse Walker and his gang force their way into the Pierpont Morgan Library, holding the priceless collection of books hostage in exchange for Conklin and the car. New York City Police Commissioner Rhinelander Waldo (James Cagney) arrives and takes command of the siege. He sends men to retrieve Walker Coalhouse's infant child, but Mother refuses to give him up. This angers Father, who demands she turn the child over, and he returns to New York alone to assist Commissioner Waldo. In his absence, Mother checks out of their hotel.
Local black attorney and NAACP activist Booker T. Washington (Moses Gunn) is called in as a mediator but fails to persuade Walker to surrender, as does Father in a meeting at the library. It is here that Father discovers Younger Brother among Walker's gang, wearing black-face makeup. Conklin, who has fled, is captured by the police, and forced to call phone Coalhouse Walker at the library and apologize. Commissioner Waldo is disgusted by Conklin and his racist attitude, who he calls "a piece of slime", and announces to Conklin that he will be brought up on criminal charges, but the Commissioner yet cannot submit to terrorist demands. Coalhouse Walker ultimately agrees to surrender if Waldo will permit his supporters to safely depart in his restored car. Waldo agrees after Father volunteers to stay inside the library as a hostage. Younger Brother and the rest of Walker's supporters escape in the car, and he drives Father out the library soon after. He prays, seeming ready to blow himself up, but instead surrenders to the police. As he steps out of the building with his hands raised, Waldo orders a sniper to shoot him dead.
The film ends with another newsreel montage set a few years later: Evelyn dances in vaudeville and is a major stage and silent film star. Harry Thaw is released from an asylum. Harry Houdini escapes from a straight jacket while dangling several stories above the ground, while below him, the newspapers announce that war in Europe has been declared (the start of the first world war in 1914). Younger Brother returns to working at the factory, but now with idealistic and radical views on life and the races. In the final shot, Father watches from the house in New Rochelle as Mother departs with Tateh and Coalhouse's son.