Long before Lassie and Rin Tin Tin, there was the first Dog Hero of the silver screen. That dog's name was Jean, the Vitagraph Dog. Around 1907, Maine resident and aspiring writer Laurence Trimble moved to New York City with his dog, Jean. An article he sold to a local magazine paved the way for the two of them to visit Vitagraph Studios to do a story on film making. Wikipedia
The definitive Wikipedia entry for Vitagraph Dog. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Vitagraph_Dog