This is what we found on Wikipedia regarding the Chicago The Musical:

Chicago is a 1975 American musical with music by John Kander, lyrics by Fred Ebb, and book by Ebb and Bob Fosse. Set in Chicago in the Jazz Age, the musical is based on a 1926 play of the same title by Maurine Dallas Watkins about actual criminals and crimes on which she reported. The story is a satire on corruption in the administration of criminal justice and the concept of the "celebrity criminal".

The world premiere of the musical was a Broadway tryout from April 8, 1975, to May 3, 1975, at the Forrest Theatre in Philadelphia. The original Broadway production opened on June 3, 1975 at the 46th Street Theatre and ran for 936 performances, until August 27, 1977. Fosse directed and choreographed the original production, and his style is strongly identified with the show. It debuted in the West End in 1979, where it ran for 600 performances. Chicago was revived on Broadway in 1996, and a year later in the West End.

The 1996 Broadway production holds the record as the longest-running musical revival and the longest-running American musical in Broadway history. It is the second longest-running show ever to run on Broadway, behind only The Phantom of the Opera. Chicago surpassed Cats on November 23, 2014, when it played its 7,486th performance. The West End revival became the longest-running American musical in West End history. The ongoing 1996 revival of Chicago is the longest-running show currently on Broadway. Chicago has been staged in numerous productions around the world, and has toured extensively in the United States and United Kingdom. The 2002 film adaptation of the musical won the Academy Award for Best Picture.