Metro's Transportation Library and Archive just posted an interactive timeline of LA's transit agencies dating back to 1874 and an organizational flow chart of how these agencies were related: 220 agencies in 140 years!! And when you click on the icon of a transit agency you can get more info on each operator as well as photos. It may be more information about LA transit than anyone wants to know, but the sheer volume is impressive in a city everyone thinks was built up around the car.

So many people have visited the Metro Library site that you have to click on the link under "Max views exceeded" -- to go here.