Porky Pig is a child forced to learn the Pledge of Allegiance. He becomes quickly bored and falls asleep. In his dream, Uncle Sam (voiced by John Deering) comes to life and teaches Porky about history from Colonial America through the American Revolutionary War to the expansion of the American Old West, briefly alluding to Abraham Lincoln. Upon awakening, Porky snaps into a salute and recites the pledge as the Flag of the United States waves overhead and the words "The End" pan over the waving flag.
There are no Merrie Melodies rings at the end, as in other shorts, or the words "That's All, Folks!"
The Flag of the United States has only 48 stars, as this short was made before Hawaii and Alaska were admitted to the Union. Also, this Pledge of Allegiance as recited by Porky does not yet include the phrase "under God" as that phrase was not added until 1954.
The original ending title card was cut from the original negative when the cartoon was re-released into the Blue Ribbon Merrie Melodies program on August 25, 1945 during the 1944-45 season (evident from the style opening Color Rings used: orange rings with a black background) and again on September 12, 1953 during the 1953-54 season (evident from the style opening rings used: orange rings with a blue background).
Since the cartoon was reissued in 1945 (after Schlesinger sold the studio and retired), the second reissue retains the first reissue's ending card after the flag fades out. Other cartoons that kept the first Blue Ribbon ending title card were "Rhapsody in Rivets" and "The Trial of Mr. Wolf", the latter having its original titles restored on DVD. The version with the 1945 closing card can also be found on Volume 2 of the LaserDisc set The Golden Age of Looney Tunes.
In 2004, however, the original ending title card was found and restored for release on the second volume of the Looney Tunes Golden Collection. This copy retains the 1953-54 Blue Ribbon opening, but also contains the original "The End" card fading in on the flag instead of a fade to black.
"Old Glory" is Jones's first short to feature Porky Pig. It is also Porky's first appearance in a color Merrie Melody since his debut in 1935's "I Haven't Got a Hat". This was also his first short in three-color Technicolor, as the former mentioned was in two-color Technicolor.
Legend has it that during the late 1960s, "Old Glory" was regularly screened between rock acts at the Fillmore in San Francisco. Supposedly the Fillmore's patrons drew great amusement from a pig (or "cop" in 60s slang) saluting the American flag.[citation needed|date=]
"Old Glory" premiered at the famed Carthay Circle Theater at Los Angeles on July 1, 1939 - three days before Independence Day.
The animation in "Old Glory" is realistic and heavily rotoscoped, which is different from the usual Warner Bros. style. Director Chuck Jones was known for his Disney-like style during this period, and Schlesinger assigned him to make this cartoon for that reason. The scene with Patrick Henry saying his "Give Me Liberty" speech was rotoscoped from the Warner Bros. color 2-reel historical short, "Give Me Liberty", which won the Academy Award for Best Short Subject in 1936.
The copyright was renewed on 1967 shortly before the short would have been due for public domain laws in the United States.
American and European 1995 Turner prints are known to exist for this short.
The Viddy-Oh! For Kids Cartoon Festivals tape print (which axes out the cartoon's opening rings) for some reason airs on the Polish TV channels TV Puls and Puls 2, , which means that this is one of the very rare non-dubbed pre-1948 Looney Tunes cartoon airings on European networks after 1995, even though a European 1995 dubbed print does exist.
This cartoon's Cartoon Festivals tape print (which axes out the cartoon's opening rings) also airs on Cartoon Network/Boomerang Latin America and Tooncast, alternately with the cartoon's USA 1995 dubbed version print.