Sweet has been a playwright, screenwriter, lyricist, critic, journalist, teacher, theatre historian, and sometime songwriter and director. He was a resident member of Chicago's Victory Gardens Theater, where thirteen of his plays—including Flyovers, Porch, The Action Against Sol Schumann, The Value of Names, Berlin '45, With and Without, Court-Martial at Fort Devens, Class Dismissed, and Bluff have been produced. In recent years he has performed a solo piece, You Only Shoot the Ones You Love (which premiered in the New York Fringe) and authored Kunstler, a play about William Kunstler, which premiered in 2013 at Hudson Stage Theater and subsequently played the New York Fringe in 2014, off-Broadway in 2017 (at 59E59th Street) and had an extended run at Barrington Stage in Pittsfield, MA in the summer of 2017. Kunstler was written for actor Jeff McCarthy. Sweet's plays are often focused on historical-political subjects. The most produced of the former is The Value of Names, a story set against the backdrop of the aftermath of the blacklist. In this play, a young actress finds herself facing the prospect of working with the director who named her father to HUAC during the McCarthy era. Since its 1983 premiere at the Actors Theatre of Louisville, Names has been revived a number of times, notably in a series of six productions starring Jack Klugman (including one at the Falcon Theatre which was nominated for "best play" in the Ovation Awards of Los Angeles; it was a remounting of the 2006 production directed by James Glossman at the George Street Playhouse in New Brunswick, NJ). An earlier play, American Enterprise, dealt with George Pullman and the 1894 strike that bears his name. It received a Kennedy Center-American Express production grant and was cited by the American Theater Critics Association as one of the three best plays to premiere in the 1990–91 season. The Action Against Sol Schumann was similarly cited by ATCA in the 2000–01 season. Sweet won the 2012 Audelco Award for best playwright for the New York production of Court-Martial at Fort Devens at the New Federal Theater. Sweet has also written for television, as well as radio adaptations of some of his plays. His work for the soap opera One Life to Live resulted in a Writers Guild of America Award for writing for a daytime serial in 1992 and an Emmy nomination. Under the title of "creative consultant," he also co-wrote the adaptation of Hugh Whitemore's Pack of Lies for the Hallmark Hall of Fame. The script, officially credited to the pseudonym Ralph Gallup, was nominated for an Emmy, and the show won a Peabody Award.