Looney Tunes were very divided up between channels.
ABC had most of the Chuck Jones ones they had been airing since the late 50's and had them in hour long blocks every Saturday.
Various other networks had collections of them that they would show in afternoons along with modern cartoons like Fox etc. Again mostly the 50's-60 stuff.
Nickelodeon used to show the really extra cheap and poorly drawn late 60's, early 70's stuff like the Ardvark, Cool Cat, and Bunny & Clyde.
Turner had the 30's and 40's collection along with all the Pink Panther shorts and MGM stuff which came on TBS and TNT.