Foghorn Leghorn literally came out of the barnyard, but the star of that barnyard was not the rooster but a character called, "Henry Hawk."
It's after awhile when, describing Foghorn, another historian notes "this overbearing rooster" started to become a recognizable character. From there, his star began to rise and "Henry" began to fade from the scene.
Joe Dante, director of the film "Looney Tunes: Back In Action," notes that Foghorn's voice and name were based on parody of a radio character called "Senator Claghorn."
Other than that, there's not much in this little feature included in the Looney Tunes Golden Collection Volume One DVD.