In the opening scene, Gus and all of the "Darkie" stable hands, are dancing and singing "Liza Lee". The center of the celebration is the arrival of "Big Boy", the newborn colt who holds the key to the future of the Bedford family's plantation, the setting of the film.
Gus spends his spare time at the stable, grooming the little colt. "Big Boy", Gus praises the colt, "ya sure is pretty, ya got Greta Garbo's eyes and Clara Bow's legs, dog-gonit, if ya only could cook!" Gus manifests his affection for the colt when he sings the lullaby "My Little Sunshine."
Mrs. Bedford, played by Louise Closser Hale, walks in to see the colt. "Good morning Gus, how is Big Boy this morning?"
"Morning, Mrs. Bedford," Gus replies, "he's so weak, he couldn't even throw the Prince of Wales. But, he'll be alright. ..he's gonna grow up big and strong and win the Derby just like ya is plannin'."
"I hope so Gus, she sighs "because everything depends on you...and Big Boy."
Two years later, Big Boy is full grown and ready to race in the Kentucky Derby. Mrs. Bedford has a lot to be happy about. Not only is Big Boy ready to race, but her son Jack, played by Lloyd Hughes and her daughter Annabelle, played by Claudia Dell, have returned home after a long absence.
Jack and Annabelle exchange warm greetings with their Mother, "It sure feels good to be home Mother."
"Jack! And my baby, it's so good to have you both home."
"Mother, I'd like you to meet some friends of mine who came down for the Derby." Jack introduces his Mother to Coley Reed, played by Eddie Phillips, Doc Wilbur played by Lew Harvey and England's Premier Jockey Steve Leslie, played by Colin Campbell.
"Friends of Jack are always welcome," Mrs. Bedford says cordially.
In reality, Coley Reed and Doc Wilbur are anything but Jack's friends. While Jack was in New York, he had gotten into a poker game with them. Doc and Coley had cheated him and Jack lost heavily. Jack didn't have the cash to pay his debt; Coley talked him into signing a check for his losses although there wasn't money in the bank to cover the check.
Big Boy was favored to win the Derby, and Coley knew if he could fix it so another nag would win, he could make a bundle. Coley's plan was to have Steve Leslie ride Big Boy in the Derby. Steve could hold Big Boy back allowing "their" horse to win easily.
"Mother," Jack approaches Mrs. Bedford, "Coley Reed and Doc Wilbur said Big Boy is a cinch to win the Derby if he has the proper jockey!"
"Big Boy has a jockey," Mrs. Bedford replies, "Gus is going to ride him. Gus' family has always ridden our horses."
"I know Mother," pleads Jack, "but I think we should forget such traditions."
"We Bedfords must never forget what our Darkies remember. Now there was Gus' Grandfather. It was in the Autumn of 1870 when he performed an act of great loyalty."
In a flashback scene, we are taken back to the post Civil War days of Kentucky. Gus' Grandfather (played by Jolson, of course) is heard singing some negro spirituals. Just as Gus finishes his concert, two riders storm into the plantation.
Gus meets Bully John Bagby, played by Noah Beery Sr., and they instantly dislike one another. Bagby wants to horse whip Gus at six o'clock, but Gus plans to be long gone by half past five.
Gus knows that Bagby is only there to cause trouble. "There's a skunk in the wood pile and I am going to catch him," says Gus.
Bagby shoots John Bedford and kidnaps his fiancee, but Gus is hot on his trail. Bagby tries to flee on horseback, but Gus chases right after him. Finally, Gus brings Bagby back dragging him from a rope. "Mercy! Mercy," cries Bagby.
"I'll give ya mercy," smiles Gus, "so you're the tomato from New Orleans, eh! Well as far as I'm concerned, you're only a Hollywood dapper! "
"Praise the lord! Praise the lord," shouts John Bedford as Gus drags Bagby back to the plantation.
"Praise the lord...say give me a little credit will ya," moans Gus.
Jack and Annabelle are heard laughing as Mrs. Bedford finishes the story on Gus' ancestor. Jack then gets up to walk down to the stables.
On the way. Jack is stopped by Coley and Doc. "How did you make out kid?" asked Coley.
"No good. Mother wants Gus to ride Big Boy."
"Oh yeah, well, we'll just see about that," Goley sneers.
"You'll never talk Mother into letting Steve ride Big Boy," says Jack.
"I'm not going to try. You're going to fix it so Gus gets the gate. Then she'll have to let Steve ride in the race," saya Coley with contempt.
"I won't do it," Jack protests.
"Oh no? Well, I once knew someone who got twenty years for passing a 'bum' check. In this case a certain young lady named Dolly Graham ia holding your check. Why? Because I fixed it."
Gus strolls by. "Oh Gus!" calls Coley, "I think your boss has something he wants to tell you...don't you Jack!"
Jack tells Gus to exercise Big Boy at 3:00 a.m. instead of at 6:00 a.m. which would make the horse nervous and restless.
"I can't do that Mr. Jack. If Mr. Jim were to find out, he'd fire me!" "Look Gus, am I your boss?"
"You're my boss."
"Do I have common sense?"
"You're my boss!"
"You do as you're told," says Doc. "If he tells you to take the horse out, you do it!"
Gus complies with Jack's instructions and Big Boy is a wreck.
Jack is so guilt ridden that he gets drunk at the party his Mother is giving to welcome home her children. "Come on Mr. Jack, lets go upstairs before your Mother sees you like this."
Suddenly, Big Boy's trainer Jim, played by Franklin Batie, comes running up to the house. "Mrs. Bedford! I've got to speak with you, it's very important. Big Boy has been tampered with! I didn't know until a few minutes ago. One of the Williams's stable boys told me that they saw Gus riding and exercising Big Boy continously this morning at 3:00 a.m. contrary to my orders! Now he's all tense and nervous!"
"Gus! Come here this instant," orders Mrs. Bedford. "What is the meaning of this?"
"Trying to throw the Kentucky Derby, were you," snapped Jim!
"Why Mrs. Bedford, Mr. Jim...I....well...I was only doing what Mr. Jack told me to do," Gus tries to explain.
"Jack! Come here! Did you tell Gus to take Big Boy out at 3:00 a.m. this morning?"
"No Mother, I did not," Jack lies.
"My son wouldn't lie. You're discharged. See that he leaves the place immediately," orders Mrs. Bedford.
Fate has dealt Gus a severe blow, but he isn't one to worry when skies are grey; he knows tomorrow is another day.
Click to hear Al Jolson sing
"Hooray for Baby and Me"
"What will ya have Joe?"
"Nothing I guess. I changed in a hurry and forgot my wallet."
"That's alright, I understand. I'll take care of everything," Gus assures Joe. Gus then tries to convince the patrons that the food is bad, so Joe can get a free meal.
Meanwhile Joe overhears Doc Wilbur and Dolly Graham arguing over Coley Reed. "Look Doc, I helped Coley frame Jack Bedford with that phony bum check. Now he's on the make for that Bedford dame. Well I'm his wife," Dolly confesses "and I won't stand for it. If Coley doesn't meet me here I'll squeal on him tonight!"
Gus returns to Joe's table with a plate of oysters. "Gus I just heard Doc Wilbur and that woman over there talking about how she helped frame Jack. Something about a bad check. They have Jack in their power and they don't want Big Boy to win. They had you fired," reveals Joe.
"That makes me so mad Joe!"
At that moment, Dolly puts the check down the front of her dress for safe keeping. "Joe, I gotta get that check!", Gus declares.
Gus tells one of the waiters to turn off the lights when he whistles. "The boss is playin' a little joke on some of his friends... You do as I say and we'll have some fun!"
Gus and Joe walk over to Coley's table. By this time Coley has arrived and now the fur is really flying. "Hey, hey, where do you think you are? You can't argue like this in a public place. This ain't your home ya know!"
Doc Wilbur jumps to his feet. "Where did you come from?", he asked.
"A reindeer brought me!" Gus says sarcastically.
"Are you looking for trouble," shouts Doc.
"Yeah! Do ya got any," Gus chimes in.
Doc Wilbur throws a punch, but misses and Gus gives out with a long whistle.
When the lights go off, Gus tries to get the check from Dolly.
"Coley, somebody is after the check!" screams Dolly in fright.
After Coley, Doc, and Dolly leave, Joe asks, "Did you get the check Gus?"
"Did I get the check? Say, I'm an ol' check getter. When I set out to get me a check I ... I ... Oooooh Mr. Joe, what must that woman think of me?" The only thing Gus managed to retrieve was a piece of Dolly's underclothing.
It's Derby Day and Gus cannot stay away from the track and Big Boy any longer. He asks Jim to let him stay and calm Big Boy down for the race.
"Don't you harm him," Jim warns.
"Harm him, Mr. Jim how can you say a thing like that? I love that horse and he loves me! When that horse looks at me, it's love! He don't want a new hat!"
"OK, Gus," Jim agrees, you stay and calm him for the race."
As Jim leaves the stable he sees Joe, Jack and Annabelle running towards him. "Jim! Big Boy has been framed to lose! Steve Leslie is under orders to hold him back! The plot all hinges around a bad check, which Dolly Graham destroyed in my presence this morning. Dolly is Coley Reed's wife!"
"Coley Reed's wife!", exclaims Annabelle.
"Yes, he's been married all along."
"What about the race, who's going to ride Big Boy?"
"Why not let Gus ride Big Boy, he's here!"
"Gus!" shouts Jim.
"Did someone call me?" asks Gus.
"Gus you're going to ride Big Boy and you're gonna win, aren't you!"
"If I don't win, the other horses won't finish!"
Yes, Gus and Big Boy do win the Kentucky Derby, "Lucky Break," the horse Coley and Doc bet so heavily on comes in last, and Coley and his gang get out of town quick.
Gus rides Big Boy over to the winner's circle surrounded by a mass of reporters. "Gus! Tell us how you won the race!" Gus hurries up to the microphone and says "Listen, if ya give me a couple of minutes, I'll tell ya how I won the biggest race of the year, The Kentucky Derby!"
Gus turns away from the reporters. Suddenly the blackface Gus becomes the white face Al Jolson. The scene has changed to a theatre and Jolson explains, "I told the writer that I wouldn't play in the picture unless I won...after all, I played too many horses who have finished last!"
Mr. Jolson then introduces the cast to the audience.
"Say Al, no Jolson picture would be complete without a Jolson song.
"What should I sing?"
Click to hear Al Jolson sing
"Tomorrow Is Another Day"
The rest of the audience groans, and turns to walk out.
"Hey, wait a minute folks, I'm not goin' to sing 'Sonny Boy'... but I do have a song."
Jolson sings "Tomorrow is Another Day," and the film ends.