Welcome Back, Kotter was a 70s sitcom about a Brooklyn native returning to his old stomping grounds, getting a job as a teacher at his alma mater, James Buchanan High. The wisecracking Gabe Kotter got the toughest assignment in school, history class with the "Sweathogs," remedial students thought to be beyond redemption by the uptight vice-principal, Mr. Woodman. Kotter didn't give heed to the bad talk about his students because, after all, he had also been a Sweathog during his youth.

Kotter's class was full of odd characters, starting with Vinnie Barbarino (a young John Travolta), self-proclaimed leader of the group and resident heartthrob. Vinnie wasn't the sharpest pencil in class and loved to love the ladies, even though most of his romantic aspirations went sour. Juan Eppstein was a proud Puerto Rican Jew, tough and cocky. Freddie "Boom Boom" Washington was a star basketball player and calm voice of reason when things got heated. Arnold Horshack, a shy nerdy kid, often broke out into a laugh that would make hyenas everywhere sit up and take notice.

Mr. Woodman was the sworn enemy of the Sweathogs, but also a dedicated teacher who memorably wore historical costumes to class to get his lessons across. Kotter's wife, Julie, was smart and supportive of her husband, even when a constant stream of Sweathogs paraded through their modest apartment. In later episodes, Kotter took over Woodman's job as vice-principal and Julie joined the school stuff as a secretary.

The antics of the core Sweathog group was the main source of laughs in this very 70s comedy. Bell bottoms, afro hairdos, thick mustaches and wide lapels were everywhere in Welcome Back, Kotter. The boys were unruly but not malicious and much of their mischief was silly instead of dangerous. The show spawned a myriad catchphrases, due to each characters distinctive way of speaking (or laughing, in Horshack's case). Vinnie would often spout "Up your nose with a rubber hose!" which was the wittiest retort he could come up with. Smooth operator Boom Boom's deep bass greeting of "Hi there" was guaranteed to make girls swoon and fellas tremble. Eppstein demonstrated ample chutzpah with daily notes excusing his behavior, always signed "Eppstein's Mother," leaving no doubt as to who was actually the author of the note. Wimpy Arnold, with his braying laugh, was an easy target of jokes but he was the only Sweathog to leave the remedial class for more advanced lessons.

Much of the show was based on comedian Gabe Kaplan's (Kotter) routines about kids he had known in various remedial classes. Names were changed (except for Horshack, that's comedy gold) but the characters came through loud and clear. The series also had a hit theme song by former Lovin' Spoonful singer, John Sebastian, that reached the #1 spot in 1976.