The series was built around Throckmorton P. Gildersleeve, a regular character from the radio situation comedy Fibber McGee and Molly.

"Gildy" grew so popular that Kraft Foods—promoting its Parkay margarine—sponsored a new series featuring Peary's somewhat mellowed and always befuddled Gildersleeve as the head of his own family.

It moves the title character from the McGees' Wistful Vista to Summerfield, where Gildersleeve oversees his late sister and brother-in-law's estate (said to have both been killed in a car accident) and rears his orphaned niece and nephew, Marjorie and Leroy Forrester.

Marjorie (originally played by Lurene Tuttle, later by Louise Erickson and Mary Lee Robb) matured to a young woman through the 1940s.

During the ninth season (September 1949-June 1950) she met and married Walter "Bronco" Thompson (Richard Crenna), star football player at the local college.

Leroy (Walter Tetley), who remained age 10–11 during most of the 1940s, began to grow up in the spring of 1949, establishing relationships with the girls in the Bullard home across the street.

Outside the home, Gildersleeve's closest association was with the executor of his brother-in-law's estate, Judge Horace Hooker (Earle Ross), with whom he had many battles during the first few broadcast seasons.

In the fourth season, these three friends, along with Police Chief Donald Gates (Ken Christy), formed the nucleus of the Jolly Boys Club, whose activities revolve around practicing barbershop quartet songs between sips of Coca-Cola.

Starting in mid 1952, some of the program's longtime characters (Judge Hooker, Floyd Munson, Marjorie and her husband, Bronco) were missing for months at a time.

Child actor Michael Winkelman, later of The Real McCoys, also made his first television appearance on the show in the role of 9-year-old Bruce Fuller.

[7] After joining Jim and Marian Jordan (as Fibber McGee and Molly) and fellow radio favorite Edgar Bergen in Look Who's Laughing (1941) and Here We Go Again (1942), Peary received top billing for a brief series of RKO films.

The Great Gildersleeve (1942) also carried Randolph from the radio cast to the screen, with Nancy Gates as Marjorie and Freddie Mercer as Leroy.

This multi-film release includes a fifth film, Seven Days' Leave, a 1942 Lucille Ball/Victor Mature musical comedy in which Peary co-stars as the Throckmorton P. Gildersleeve character.

The Gildersleeve character was parodied in the 1945 Bugs Bunny cartoon Hare Conditioned, in which the rabbit distracts a menacing department store manager by telling him that he sounds "just like that guy on the radio, the Great Gildersneeze!"

The second album, Children's Stories as Told by the Great Gildersleeve, in 1946, featured "Hansel and Gretel" and "The Brave Little Tailor", again with orchestral accompaniment.

The third and final album in the series, reverting to the title of the first and released in 1947, included "Snow-White and Rose-Red" and "Cinderella", once more with full orchestral accompaniment.

In 1950, Peary, as "the Great Gildersleeve", narrated a single 78rpm recording for Capitol of Dr. Seuss' Gerald McBoing-Boing with full orchestration and sound effects.