Depending on how you look at it, both answers of "the 70s'" & "1987" are correct.
The Kids of Degrassi Street's first episode was produced in 1979! TKoDS was a series which incorporated the "Degrassi" name and was made by the same producers (Linda Schuyler, et al)! It was about young kids who lived on on that said Street, and dealt with the trials and tribulations of growing up. Though made by the same producers, the characters and storyline universe are totally different!
Degrassi Junior High, which started airing in 1987, is the first show that incorporates the storyline universe that is used in Degrassi: TNG with characters like Joey, Spike, Caitlin, & Archie "Snake" Simpson!
I hope that explanation didn't go over all your heads!
