The show starred Shirley Jones as mother Shirley Partridge and David Cassidy (Jones' real life stepson) as Keith Partridge. Susan Dey played Laurie, Danny Bonaduce played Danny, Jeremy Gelbwaks (later replaced by Brian Forster) played Chris, and Suzanne Crough played Tracy Partridge. Dave Madden played Reuben Kincaid, who was their manager and booked all their tours.
https://en.wikipedia.org/wiki/Partridge_Family