Based on Eugene O'Neill's only comedy, a family experiences July 4th as their graduating son, rejected by his girlfriend, goes drinking with a swift woman.
At a school dance Richard (Eric Linden) promises to love Muriel McComber (Cecilia Parker) always though she hasn't let him kiss her. His uncle Sid (Wallace Beery) drinks before leaving for a new job; Lily (Aline MacMahon) won't marry him because of his drinking. Richard's mother Essie (Spring Byington) complains of his reading, which includes Oscar Wilde and G. B. Shaw. At graduation Richard gives the valedictorian address; but his father Nat (Lionel Barrymore) stops him before he can say his previous platitudes are all capitalist lies. Muriel agrees to go boating with Richard. July 4th starts out noisy as Tommy (Mickey Rooney) explodes firecrackers. Sid comes home and hides his suitcases. Dave McComber (Charley Grapewin) tells Nat that Richard is corrupting his daughter with poems and wants him to punish the boy; they argue. Nat and Sid enjoy reading Swinburne's poetry. Nat asks Richard about Muriel, and he says he loves her. Nat gives him Muriel's letter telling him not to see her again.
Sid invites Lily to the fireworks. Wint tells Richard he's got two swift girls. Nat returns with drunk Sid and slaps Essie on the rear. Nat says he gave Sid his job back and asks the family to understand "celebrating" Sid. At lunch they laugh at Sid and Nat, who says blue fish oil poisons him, though Essie has been feeding him it for years. Lily blames them for humoring Sid, but Richard criticizes Lily for turning down Sid. Smoking Wint takes Richard to a bar. Richard buys drinks for Belle (Helen Flint). She sits in his lap and kisses him. At 10:30 Essie is worried, and Nat asks Arthur to sing. Richard gives Belle $5 for her rent and drinks another, asking her to reform. Richard gets drunk and is thrown out for being under age. Sid apologizes to Lily and cries; she forgives him. Richard comes home soused, and Sid takes care of him.
Nat cancels the McComber ad in his paper and receives a letter from Belle about the bar giving Richard alcohol. Muriel finds Richard, and he tells her he went out with a chorus girl and kissed her. She says her father made her write the letter. They make up, and she lets him kiss her. Richard tells his father he was a fool, and Nat advises his son about women who can ruin a man's life. Nat says Richard must go to Yale. Sid and Lily drink on the porch, and Richard kisses both his parents goodnight. Nat quotes the Rubaiyat about spring and youth and tells Essie he appreciates autumn with her.
This story deals pleasantly with the dangers of alcohol and loose women, as we see a young intellectual coming of age in a gentle era after the turn of the century.