Actually, Iwas going to write considerably more about this, but Sluggo kept crashing on me, and now I don't have the time. So just take my word for it and go look at America Hurrah, a regional history site in San Francisco. They have a decent index on their home page. And be sure to look at the Muybridge Panorama of 1878, one of the most interesting photographic documents of the 19th century. Lots of other good stuff on the site, too.