Edison held the rights to the motion picture camera and demanded compensation when they were used. If Edison did not receive payments from a production he was not above sending thugs to the movie sets to assault the cast and crew, let alone use the authorities. Early film makers wanted to put some geographic distance between them and Edison for safety.

So why CA? Remember that lighting technology in the early days wasn't ideal. Movie sets were either outside or inside what basically looked like greenhouses to let as much sun in. Southern California's climate provided a maximum amount of shooting days per year.

The nearby Mexican border also provided a bit of an escape route.

Eventually of course, Edison followed them west and the attacks continued. A man named Thomas Ince came up with solution in which he set up his entire operation within a canyon with only one way in or out. He then posted a small army of guards at that entrance to keep Edison's thugs away.

Ince discovered something else though. With his entire operation self enclosed, his productions became incredibly efficient. The Edison attacks eventually stopped, but Ince's operation was still copied by other filmmakers for its other benefits and became the prototype for what we now know as a movie studio.

If the name Ince sounds familiar, he's the man who was rumored to be murdered by Hearst on Hearst's yacht (supposedly Hearst was aiming for Chaplin who was supposedly having an affair with Marian Davies).

Sources:

An Introduction to Film History by Thompson and Bordwell.

What Happens Next by Marc Norman

A professor of mine insisted that Florida was the center of the American film industry before the state government kicked them out through a variety of legislation.

Could anyone elaborate on this?