Major Amberson created the family fortune in the 1870’s. When Isabel, his daughter, was about twenty years old, she was courted by two men: Wilbur Minafer, a quiet businessman, and Eugene Morgan, a debt-ridden lawyer. Morgan destroyed his chances in a drinking incident on the Amberson estate. Isabel married Wilbur, and their only child was George Amberson Minafer. Isabel spoiled her wild boy. George treated others with contempt and was once expelled from a prep school for his bad behavior. The townspeople hoped to see George get his comeuppance.
When George was an eighteen-year-old college student, a ball was held in his honor at the Amberson mansion. Here George met Eugene Morgan, his mother’s former suitor, and fell in love with his nineteen-year-old daughter, Lucy. Eugene had left town at the time Isabel dismissed him, become an inventor, and returned to town twenty years later to manufacture horseless carriages. George informed Lucy that he had no career plans. During their sleigh ride the next day, George attempted to embarrass the inventor by racing his sleigh past Morgan’s inoperative horseless carriage. George’s sleigh crashed, and he and Lucy had to hitch a ride back into town on the new vehicle. After George returned home for summer vacation, he renewed his relationship with Lucy. When she and her father attended one of the Major’s weekly Sunday dinners, the latter revealed that Isabel and Eugene had once been engaged. On the night before George returned to college, Isabel told him of Wilbur’s declining health. His father was deeply worried because he and George’s uncle, George Amberson, had tied up much of the family’s assets in a company owned by their friends, an investment that was turning sour.
During the following summer, George proposed to Lucy when he heard a false rumor that she was engaged to Fred Kinney. Though she declined to say either yes or no at that time, she promised to settle the matter before he returned to school. On George’s final night before returning to college, Lucy still left their relationship unsettled. She told him that they were "almost" engaged. While back at college, Isabel wrote George that she had gotten the ailing Wilbur to take a vacation and that his uncle, Sydney Amberson, and his wife had taken their one-third share of the Amberson fortune. Then Wilbur died, and his business failure left Uncle George and Fanny broke. George Minafer gave his father’s insurance money to Fanny as compensation. After George’s graduation from college, he was horrified to see five new houses on the family estate—the Major’s attempt to recoup the family fortune. George became increasingly hostile to both Eugene Morgan and his automobiles. Lucy refused to go beyond their "almost" engagement because George, unlike her father, refused to pursue a career.
George then insulted Eugene Morgan during a Sunday dinner. Angered by his differences with Lucy and by a rumor that Isabel had always been in love with Eugene, George confronted the rumormonger, Mrs. Johnson, and then barred the industrialist from his house. George then told Isabel that he had to protect the Amberson name from scandal, and bullied her into ceasing all contact with Eugene Morgan. George subsequently told Lucy that he and Isabel were to leave the country indefinitely.
Then the Amberson holdings fell into decay, the Major’s new houses proved a failure, and Uncle George and Fanny invested heavily in an ill-fated headlight invention. Against Uncle George’s advice, Fanny secretly staked all of her money on the scheme. After several years abroad, George brought his mother back when she was gravely ill. As she lay dying, George refused to let Eugene see his old flame one last time. Isabel later told her son that she had wanted to see Morgan once more. With Isabel’s demise, the Major lost all interest in business. When Fanny told George that the gossip had died out soon after his departure, George then feared that his interference had been agrave error. Then the headlight scheme collapsed, and Uncle George revealed that Isabel had never received a deed for her house. When Major Amberson died, the Amberson estate was bankrupt, and Sydney and Amelia, having taken the best part of it, then refused to help. Uncle George was awarded a consulship in another city, while George was to room with Fanny and study law. When Fanny confessed that she was destitute, George had to accept a dangerous job involving explosives in order to support her. The growing city quickly effaced all traces of the Ambersons, and George felt the humiliation the townspeople had long ago desired. George was then seriously injured by an automobile. When Eugene was away on business, he discovered that both he and Lucy had had a vision of Isabel. His subsequent visit to a psychic and a second vision of Isabel suggested to him that she wanted him to help George. Upon returning home, Eugene rushed to George’s hospital room and found Lucy and Fanny already there. George begged his forgiveness, and Eugene realized that he could regain his connection with Isabel by helping her son.