To clarify how these distinct family histories align across twentieth-century cinema, the historical records show clear separations in lineage, geography, and legal naming conventions:
| Performer | Legal Birth Name | Surname Origin | Union/Career Conflict |
|---|---|---|---|
| Buster Keaton (1895, 1966) | Joseph Frank Keaton VI | Generational family surname from paternal lineage | None; "Buster" given as a childhood vaudeville nickname |
| Diane Keaton (1946, 2025) | Diane Hall | Maternal maiden name (Dorothy Keaton) | Actors' Equity Association duplicate name collision in 1966 |
| Michael Keaton (b. 1951) | Michael John Douglas | Arbitrary choice selected from a phone book | Screen Actors Guild duplicate name collision in 1975 |
