Welcome Back, Kotter is an American sitcom starring Gabe Kaplan as a wisecracking, high school teacher in charge of a racially and ethnically diverse remedial class called the "Sweathogs". The show also features a young John Travolta and was largely responsible for making him a star. Recorded in front of a live studio audience, it originally aired on the ABC television network from September 9, 1975, to May 17, 1979.