Burbank, California, was the site of America's first monorail. In the upper left of this picture, you can see the "Aerial Swallow" or Aerial Trolley Car, running on a line across the ranch owned by its inventor, Joseph Wesley Fawkes.
Fawkes built the experimental line—which ran between what is now Lake and Flower Streets in Burbank—in hopes that the city would adopt it as the new, local form of public transportation. But, the next year, Burbank chose to invest in an electric streetcar line, instead. The Aerial Swallow never made it off of Fawkes' ranch.
You can see some great up-close shots of the Swallow at the How To Be a Retronaut blog. That blog dates the monorail to 1911. I'm using the date given by the University of Southern California digital library.