He was the leader of his gang of four his fellow Sweathogs, his name is Vinnie Barbarino, and Kotter is the teacher, the first episode shows Kotter as a newly assigned teacher at James Buchanan high. As Kotter enters his classroom, Barbarino is sitting on the teacher's desk. Seeing Kotter he takes his own seat. He and his first fellow Sweathogs respond to Kotter's presence like automatons as the teacher tells his students that he wants to "know who you are" Kotter motions to the Sweathogs on one side of the room to begin introducing themselves. Now comes Barbarino's first words on the show : "No. No, we are gonna start over here." he stands up and smiles mischievously "Barbarino. Vinnie Barbarino" he declares "This is my place and these are my people". The show through August 10, 1979.

With Welcome back, Kotter, he turned a star. One magazine in April 1977 wrote: "John Travolta from A to Z! What makes him so sexy" They said : "A, is for attractive whether he is in a tuxedo or jeans, John is always manages to look absolutely outasight" "B is for blue eyes no girl can resist! Whether sparkling with, happiness or flashing in anger they hypnotize!"

The TV Stars Today even sponsored "The John Travolta Official fan club" At the height of his popularity in WBK, Saturday night fever and Grease, Travolta became one of his generation's premiere pinup boy. He was posed as Valentino.