15. How did Joseph Keaton VI end up with the name "Buster"?
From Quiz Buster Keaton: The Man and the Myths
Answer:
As a baby, he emerged unscathed from a tumble down the stairs.
Accounts differ as to how old little Joseph was when he took the famous spill that led a bystander to pronounce, "My, what a buster!" Keaton himself claimed that he was six months old. Biographers believe he was probably closer to 18 months old. But either way, the name clearly stuck. Nobody after that -- not even his wives or grandchildren -- called him anything but Buster (though the grandkids prefaced it with "Grandpa"). It's a name he literally took to the grave, where his headstone reads simply, "Buster Keaton 1895 - 1966".
As for Buster's claim that it was Harry Houdini who gave him the moniker, this myth was probably started by Buster's father, Joseph Keaton V. The Keatons did travel the vaudeville circuit with Houdini and his wife. The two families were close friends, with Joe and wife Myra naming their second child Harry in Houdini's honor. But there's no evidence that Houdini and the Keatons crossed paths until after Buster had already picked up the name he'd use the rest of his life.
Buster himself seemed to have been the originator of another myth, that he was the first to use Buster as a name, but according to US Census data it was just not true. The name Buster was in the top 1000 names clear back to 1880 -- fifteen years before Buster's birth. It is, however, possible that Buster Keaton's popularity sparked the use of Buster as a nickname.