The film, featuring music by the Sherman Brothers, was nominated for an Academy Award for Best Costume Design by Bill Thomas.

The screenplay by A. J. Carothers was adapted from the play, based on the book My Philadelphia Father by Cordelia Drexel Biddle.

[4][5][6] In autumn of 1916, Irish immigrant John Lawless (Tommy Steele) has applied for a butler position with eccentric Philadelphia millionaire Anthony J. Drexel Biddle (Fred MacMurray).

Their daughter, Cordy (Lesley Ann Warren), is a tomboy with a mean right hook who was educated by private tutors and has had limited contact with conventional society.

He tells Cordy that he is fascinated with the invention of the automobile and wants to head to Detroit, Michigan, to make his fortune there, instead of taking over his family's tobacco business.

He does not want to give up his little girl, but after meeting Angier and witnessing first-hand his Jiu Jitsu fighting skills, Mr. Biddle takes a liking to him and accepts the engagement.

The tension reaches a climax when Cordy learns that Angier has abandoned his plans for Detroit, and is instead taking his place in the family business, following his mother's wishes.

A car with two people (presumably Cordie and Angie) drives toward a city skyline (presumably Detroit) dominated by factories with smoke clouding the sky at sunset.

[9] Crichton adapted the story into a play called The Happiest Millionaire,[10] which opened on Broadway on November 20, 1956, at the Lyceum Theatre.

Howard Erskine and Joseph Hayes produced the play, and Guthrie McClintic was to direct,[11] but he left the production before opening night.

[14] The Sherman Brothers, who wrote the film's music, wanted Rex Harrison for the lead role,[14][15] but Disney insisted on Fred MacMurray.

[17] Lesley Ann Warren, whom Disney had seen in the 1965 CBS television production of Rodgers and Hammerstein's Cinderella, made her screen debut in the film.

[18] The role of MacMurray's wife went to Greer Garson, who called the film "... a delightful Life with Father type picture.

[14] Disney COO Card Walker wanted to excise even more material, and the two men fought bitterly over the extent of the cuts.

[24] Robert Sherman was in England during the film's Hollywood premiere at the Pantages Theatre, but he became furious when he discovered in the Los Angeles Times that a theater in the vicinity was showing a double feature of The Shaggy Dog and The Absent-Minded Professor at a much lower price.

It was not reissued and did not appear on television until 1984, when the 164-minute version was screened at the Los Angeles International Film Expo and aired on The Disney Channel.

It is an over-decorated, over-fluffed, over-sentimentalized endeavor to pretend the lace-curtain millionaires are—or were—every bit as folksy as the old prize-fighters and the Irish brawlers in the saloon".

As for the musical numbers, I found them eminently forgettable, with the sole exception of a nicely staged Irish reel".

[31] Charles Champlin of the Los Angeles Times stated that the film was "a disappointment" and compared it unfavorably to Mary Poppins: "There is no such unity of interest and identification in The Happiest Millionaire.