Gabe Kotter, played by Gabe Kaplan, a former Sweathog, returned to his Brooklyn high school to teach a new class of delinquents. "Welcome Back, Kotter" was wildly popular during its years on the air from 1975 to 1979. From left: Robert Hegyes, Lawrence-Hilton Jacobs, John Travolta and Ron Palillo. Click through to see what the stars of the show are up to now.

In April 2011, "Good Morning America" reunited the cast of the 1970s hit show "Welcome Back, Kotter" that brought catchphrases to classrooms coast-to-coast and catapulted the sweathogs, remedial students in Mr. Kotter's high school class, into millions of young hearts.

Ron Palillo, who played Arnold Horshack on "Kotter," died of an apparent heart attack in Florida on Aug. 14, 2012. He was 63. Palillo's character was known for his phrase, "Ooh, ooh! Mr. Kotter!" and his distinct laugh. But the actor failed to find fame when the show went off the air in 1979. He had a few odd roles in movies and television shows, but not solid stardom.

Robert Hegyes played Juan Epstein on "Welcome Back, Kotter." The actor died in his Metuchen, N.J., home on Jan. 26, 2012, at age 60. After "Kotter," Hegyes starred in "Cagney and Lacey," as well as "NewsRadio," "Diagnosis Murder" and "The Drew Carey Show." Hegyes also taught acting and wrote screenplays.

Gabe Kaplan not only starred as Mr. Kotter in the hit series, he was also the show's writer. He based the show on his experiences in an under-achieving classroom in the 1960s. After the show, Kaplan starred in several films; the most recent was 2007's "The Grand." Today, Kaplan is a champion poker player, stand-up comedian and author.

<p style="margin: 0px; font-size: 14px; font-family: Times; color: rgb(50, 51, 51);"> <span style="letter-spacing: 0.0px">John Travolta found the most fame after &quot;Kotter.&quot; The actor, who played Vinnie Barbarino, has starred in countless films, including &quot;Saturday Night Fever,&quot; &ldquo;Grease,&rdquo; and &ldquo;Pulp Fiction.&rdquo; Travolta has been married to actress Kelly Preston since 1991. The couple&rsquo;s son Jett, who was autistic, died after a seizure at their Bahamas vacation home in 2009. They also have a daughter Ella Bleu, born in 2000, and a son Benjamin, born in 2010. Travolta will return to television for the first time since &ldquo;Kotter&rdquo; to play Robert Shapiro in the FX miniseries &ldquo;American Crime Story: The People v. O.J. Simpson.&rdquo;</span></p>

<p style="margin: 0px; font-size: 14px; font-family: Times; color: rgb(50, 51, 51);"> <span style="letter-spacing: 0.0px">Marcia Strassman starred as Julie Kotter. Although she appeared in several series, including &quot;Noah Knows Best&quot; and &quot;Providence,&quot; and starred in the films &quot;Honey, I Shrunk the Kids&quot; and &quot;Honey, I Blew Up the Baby,&quot; Strassman did not become a household name. In 2007, she was diagnosed with breast cancer, which spread to her bones. She died on October 24, 2014, at age 66, after her long battle with breast cancer.</span></p>

<p style="margin: 0px; font-size: 14px; font-family: Times; color: rgb(50, 51, 51);"> <span style="letter-spacing: 0.0px">Lawrence Hilton-Jacobs played Freddie &ldquo;BoomBoom&rdquo; Washington on &quot;Kotter.&quot; After the show he appeared in a number of films including &quot;The Jacksons: An American Dream&quot; as well as television shows and commercials. But like many of his castmates, he failed to find lasting fame. A fun fact about the actor though: He sang background vocals on Rick James's &ldquo;Superfreak.&rdquo;</span></p>

Stephen Shortridge played Southern High School student Beau De Labarre on the show. In the late 1980s, Shortridge quit the acting business to concentrate on painting. He continues to present gallery showings across the United States and makes his home in Idaho with his wife and children.