Why did the movie business end up in Hollywood?

Partly to escape Thomas Edison, and partly for the sunshine. Edison owned most of the key American patents on movie cameras, and in December 1908 he and the biggest studios formed the Motion Picture Patents Company, nicknamed the Edison Trust. Kodak, which held the patent on raw film, agreed to sell film only to members. Filmmakers without a licence risked lawsuits, agents who came to seize their cameras, and in some cases hired thugs sent to wreck their shoots.

New York, close to Edison's headquarters, was a dangerous place to film without permission. Southern California was about as far away as you could get. The federal appeals court that covered it was reluctant to enforce patent claims, and if a studio was sued, Mexico, where the trust's patents did not apply, was only about a hundred miles away. Many independent filmmakers moved west.

The weather sealed it. Southern California had a warm, predictable climate with reliable sunlight for filming outdoors all year, and landscapes that could pass for deserts, jungles or great mountains. By 1912, most major film companies had production facilities in or near Los Angeles.

The irony is that the first film shot in Hollywood itself was made by a member of the trust. In 1910 the Biograph company sent D. W. Griffith west with his actors, and in the friendly little village of Hollywood he shot In Old California. The trust did not last: its patents expired in 1913, and in 1915 a court ruled it an illegal restraint of trade.